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Sample records for human streptococcus agalactiae

  1. 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...

  2. 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...

  3. Draft Genome Sequence of Streptococcus agalactiae PR06

    PubMed Central

    MZ, Irma Syakina; Teh, L. K.

    2013-01-01

    Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium that was first recognized as a causative agent of bovine mastitis. S. agalactiae has subsequently emerged as a significant cause of human diseases. Here, we report the draft genome sequence of S. agalactiae PR06, which was isolated from a septicemic patient in a local hospital in Malaysia. PMID:23766409

  4. Comparison of virulence factors and capsular types of Streptococcus agalactiae isolated from human and bovine infections.

    PubMed

    Emaneini, Mohammad; Khoramian, Babak; Jabalameli, Fereshteh; Abani, Samira; Dabiri, Hossein; Beigverdi, Reza

    2016-02-01

    Streptococcus agalactiae is a leading cause of human and bovine infections. A total of 194 S. agalactiae isolates, 55 isolates from bovines and 139 from humans, were analyzed for capsular types, virulence genes (scpB, hly, rib, bca and bac) and mobile genetic elements (IS1548 and GBSi1) using polymerase chain reaction (PCR) and multiplex PCR. Capsular type III was predominant (61%), followed by types V, II, Ib, and IV. The scpB, hly, bca and bac virulence genes were only found among human isolates. Twelve and 2 distinct virulence gene profiles were identified among human and bovine isolates respectively. The virulence gene profiles scpB- hly- IS1548- rib-bca (51%) and scpB- hly- IS1548- bca (19%) were only predominant among human isolates. The rib gene was the most common virulence gene in both human and bovine isolates. The study showed a high prevalence of virulence genes in S. agalactiae strains isolated from human infections, these result can support the idea that S. agalactiae isolated from humans and bovines are generally unrelated and probably belonged to separate populations.

  5. Discovery and Characterization of Human-Urine Utilization by Asymptomatic-Bacteriuria-Causing Streptococcus agalactiae

    PubMed Central

    Ipe, Deepak S.; Ben Zakour, Nouri L.; Sullivan, Matthew J.; Beatson, Scott A.; Ulett, Kimberly B.; Benjamin, William H.; Davies, Mark R.; Dando, Samantha J.; King, Nathan P.; Cripps, Allan W.; Dougan, Gordon

    2015-01-01

    Streptococcus agalactiae causes both symptomatic cystitis and asymptomatic bacteriuria (ABU); however, growth characteristics of S. agalactiae in human urine have not previously been reported. Here, we describe a phenotype of robust growth in human urine observed in ABU-causing S. agalactiae (ABSA) that was not seen among uropathogenic S. agalactiae (UPSA) strains isolated from patients with acute cystitis. In direct competition assays using pooled human urine inoculated with equal numbers of a prototype ABSA strain, designated ABSA 1014, and any one of several UPSA strains, measurement of the percentage of each strain recovered over time showed a markedly superior fitness of ABSA 1014 for urine growth. Comparative phenotype profiling of ABSA 1014 and UPSA strain 807, isolated from a patient with acute cystitis, using metabolic arrays of >2,500 substrates and conditions revealed unique and specific l-malic acid catabolism in ABSA 1014 that was absent in UPSA 807. Whole-genome sequencing also revealed divergence in malic enzyme-encoding genes between the strains predicted to impact the activity of the malate metabolic pathway. Comparative growth assays in urine comparing wild-type ABSA and gene-deficient mutants that were functionally inactivated for the malic enzyme metabolic pathway by targeted disruption of the maeE or maeK gene in ABSA demonstrated attenuated growth of the mutants in normal human urine as well as synthetic human urine containing malic acid. We conclude that some S. agalactiae strains can grow in human urine, and this relates in part to malic acid metabolism, which may affect the persistence or progression of S. agalactiae ABU. PMID:26553467

  6. Discovery and Characterization of Human-Urine Utilization by Asymptomatic-Bacteriuria-Causing Streptococcus agalactiae.

    PubMed

    Ipe, Deepak S; Ben Zakour, Nouri L; Sullivan, Matthew J; Beatson, Scott A; Ulett, Kimberly B; Benjamin, William H; Davies, Mark R; Dando, Samantha J; King, Nathan P; Cripps, Allan W; Schembri, Mark A; Dougan, Gordon; Ulett, Glen C

    2015-11-09

    Streptococcus agalactiae causes both symptomatic cystitis and asymptomatic bacteriuria (ABU); however, growth characteristics of S. agalactiae in human urine have not previously been reported. Here, we describe a phenotype of robust growth in human urine observed in ABU-causing S. agalactiae (ABSA) that was not seen among uropathogenic S. agalactiae (UPSA) strains isolated from patients with acute cystitis. In direct competition assays using pooled human urine inoculated with equal numbers of a prototype ABSA strain, designated ABSA 1014, and any one of several UPSA strains, measurement of the percentage of each strain recovered over time showed a markedly superior fitness of ABSA 1014 for urine growth. Comparative phenotype profiling of ABSA 1014 and UPSA strain 807, isolated from a patient with acute cystitis, using metabolic arrays of >2,500 substrates and conditions revealed unique and specific l-malic acid catabolism in ABSA 1014 that was absent in UPSA 807. Whole-genome sequencing also revealed divergence in malic enzyme-encoding genes between the strains predicted to impact the activity of the malate metabolic pathway. Comparative growth assays in urine comparing wild-type ABSA and gene-deficient mutants that were functionally inactivated for the malic enzyme metabolic pathway by targeted disruption of the maeE or maeK gene in ABSA demonstrated attenuated growth of the mutants in normal human urine as well as synthetic human urine containing malic acid. We conclude that some S. agalactiae strains can grow in human urine, and this relates in part to malic acid metabolism, which may affect the persistence or progression of S. agalactiae ABU.

  7. Streptococcus agalactiae clones infecting humans were selected and fixed through the extensive use of tetracycline.

    PubMed

    Da Cunha, Violette; Davies, Mark R; Douarre, Pierre-Emmanuel; Rosinski-Chupin, Isabelle; Margarit, Immaculada; Spinali, Sebastien; Perkins, Tim; Lechat, Pierre; Dmytruk, Nicolas; Sauvage, Elisabeth; Ma, Laurence; Romi, Benedetta; Tichit, Magali; Lopez-Sanchez, Maria-José; Descorps-Declere, Stéphane; Souche, Erika; Buchrieser, Carmen; Trieu-Cuot, Patrick; Moszer, Ivan; Clermont, Dominique; Maione, Domenico; Bouchier, Christiane; McMillan, David J; Parkhill, Julian; Telford, John L; Dougan, Gordan; Walker, Mark J; Holden, Matthew T G; Poyart, Claire; Glaser, Philippe

    2014-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal of the digestive and genitourinary tracts of humans that emerged as the leading cause of bacterial neonatal infections in Europe and North America during the 1960s. Due to the lack of epidemiological and genomic data, the reasons for this emergence are unknown. Here we show by comparative genome analysis and phylogenetic reconstruction of 229 isolates that the rise of human GBS infections corresponds to the selection and worldwide dissemination of only a few clones. The parallel expansion of the clones is preceded by the insertion of integrative and conjugative elements conferring tetracycline resistance (TcR). Thus, we propose that the use of tetracycline from 1948 onwards led in humans to the complete replacement of a diverse GBS population by only few TcR clones particularly well adapted to their host, causing the observed emergence of GBS diseases in neonates. PMID:25088811

  8. 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

  9. In silico prediction of conserved vaccine targets in Streptococcus agalactiae strains isolated from fish, cattle, and human samples.

    PubMed

    Pereira, U P; Soares, S C; Blom, J; Leal, C A G; Ramos, R T J; Guimarães, L C; Oliveira, L C; Almeida, S S; Hassan, S S; Santos, A R; Miyoshi, A; Silva, A; Tauch, A; Barh, D; Azevedo, V; Figueiredo, H C P

    2013-01-01

    Streptococcus agalactiae (Lancefield group B; group B streptococci) is a major pathogen that causes meningoencephalitis in fish, mastitis in cows, and neonatal sepsis and meningitis in humans. The available prophylactic measures for conserving human and animal health are not totally effective and have limitations. Effective vaccines against the different serotypes or genotypes of pathogenic strains from the various hosts would be useful. We used an in silico strategy to identify conserved vaccine candidates in 15 genomes of group B streptococci strains isolated from human, bovine, and fish samples. The degree of conservation, subcellular localization, and immunogenic potential of S. agalactiae proteins were investigated. We identified 36 antigenic proteins that were conserved in all 15 genomes. Among these proteins, 5 and 23 were shared only by human or fish strains, respectively. These potential vaccine targets may help develop effective vaccines that will help prevent S. agalactiae infection. PMID:24065646

  10. Extensive Adaptive Changes Occur in the Transcriptome of Streptococcus agalactiae (Group B Streptococcus) in Response to Incubation with Human Blood

    PubMed Central

    Mereghetti, Laurent; Sitkiewicz, Izabela; Green, Nicole M.; Musser, James M.

    2008-01-01

    To enhance understanding of how Streptococcus agalactiae (group B streptococcus, GBS) adapts during invasive infection, we performed a whole-genome transcriptome analysis after incubation with whole human blood. Global changes occurred in the GBS transcriptome rapidly in response to blood contact following shift from growth in a rich laboratory medium. Most (83%) of the significantly altered transcripts were down-regulated after 30 minutes of incubation in blood, and all functional categories of genes were abundantly represented. We observed complex dynamic changes in the expression of transcriptional regulators and stress response genes that allow GBS to rapidly adapt to blood. The transcripts of relatively few proven virulence genes were up-regulated during the first 90 minutes. However, a key discovery was that genes encoding proteins involved in interaction with the host coagulation/fibrinolysis system and bacterial-host interactions were rapidly up-regulated. Extensive transcript changes also occurred for genes involved in carbohydrate metabolism, including multi-functional proteins and regulators putatively involved in pathogenesis. Finally, we discovered that an incubation temperature closer to that occurring in patients with severe infection and high fever (40°C) induced additional differences in the GBS transcriptome relative to normal body temperature (37°C). Taken together, the data provide extensive new information about transcriptional adaptation of GBS exposed to human blood, a crucial step during GBS pathogenesis in invasive diseases, and identify many new leads for molecular pathogenesis research. PMID:18769548

  11. Complete genome sequence of Streptococcus agalactiae strain GBS85147 serotype of type Ia isolated from human oropharynx.

    PubMed

    de Aguiar, Edgar Lacerda; Mariano, Diego César Batista; Viana, Marcus Vinícius Canário; Benevides, Leandro de Jesus; de Souza Rocha, Flávia; de Castro Oliveira, Letícia; Pereira, Felipe Luiz; Dorella, Fernanda Alves; Leal, Carlos Augusto Gomes; de Carvalho, Alex Fiorini; Santos, Gabriela Silva; Mattos-Guaraldi, Ana Luiza; Nagao, Prescilla Emy; de Castro Soares, Siomar; Hassan, Syed Shah; Pinto, Anne Cybele; Figueiredo, Henrique César Pereira; Azevedo, Vasco

    2016-01-01

    Streptococcus agalactiae, also referred to as Group B Streptococcus, is a frequent resident of the rectovaginal tract in humans, and a major cause of neonatal infection. The pathogen can also infect adults with underlying disease, particularly the elderly and immunocompromised ones. In addition, S. agalactiae is a known fish pathogen, which compromises food safety and represents a zoonotic hazard. This study provides valuable structural, functional and evolutionary genomic information of a human S. agalactiae serotype Ia (ST-103) GBS85147 strain isolated from the oropharynx of an adult patient from Rio de Janeiro, thereby representing the first human isolate in Brazil. We used the Ion Torrent PGM platform with the 200 bp fragment library sequencing kit. The sequencing generated 578,082,183 bp, distributed among 2,973,022 reads, resulting in an approximately 246-fold mean coverage depth and was assembled using the Mira Assembler v3.9.18. The S. agalactiae strain GBS85147 comprises of a circular chromosome with a final genome length of 1,996,151 bp containing 1,915 protein-coding genes, 18 rRNA, 63 tRNA, 2 pseudogenes and a G + C content of 35.48 %. PMID:27274785

  12. Conjugative transfer of resistance determinants among human and bovine Streptococcus agalactiae.

    PubMed

    Pinto, Tatiana Castro Abreu; Costa, Natália Silva; Corrêa, Ana Beatriz de Almeida; de Oliveira, Ivi Cristina Menezes; de Mattos, Marcos Correa; Rosado, Alexandre Soares; Benchetrit, Leslie Claude

    2014-01-01

    Streptococcus agalactiae (GBS) is a major source of human perinatal diseases and bovine mastitis. Erythromycin (Ery) and tetracycline (Tet) are usually employed for preventing human and bovine infections although resistance to such agents has become common among GBS strains. Ery and Tet resistance genes are usually carried by conjugative transposons (CTns) belonging to the Tn916 family, but their presence and transferability among GBS strains have not been totally explored. Here we evaluated the presence of Tet resistance genes (tetM and tetO) and CTns among Ery-resistant (Ery-R) and Ery-susceptible (Ery-S) GBS strains isolated from human and bovine sources; and analyzed the ability for transferring resistance determinants between strains from both origins. Tet resistance and int-Tn genes were more common among Ery-R when compared to Ery-S isolates. Conjugative transfer of all resistance genes detected among the GBS strains included in this study (ermA, ermB, mef, tetM and tetO), in frequencies between 1.10(-7) and 9.10(-7), was possible from bovine donor strains to human recipient strain, but not the other way around. This is, to our knowledge, the first report of in vitro conjugation of Ery and Tet resistance genes among GBS strains recovered from different hosts. PMID:25477908

  13. The Surface Protein Srr-1 of Streptococcus agalactiae Binds Human Keratin 4 and Promotes Adherence to Epithelial HEp-2 Cells▿

    PubMed Central

    Samen, Ulrike; Eikmanns, Bernhard J.; Reinscheid, Dieter J.; Borges, Frédéric

    2007-01-01

    Streptococcus agalactiae is frequently the cause of bacterial sepsis and meningitis in neonates. In addition, it is a commensal bacterium that colonizes the mammalian gastrointestinal tract. During its commensal and pathogenic lifestyles, S. agalactiae colonizes and invades a number of host compartments, thereby interacting with different host proteins. In the present study, the serine-rich repeat protein Srr-1 from S. agalactiae was functionally investigated. Immunofluorescence microscopy showed that Srr-1 was localized on the surface of streptococcal cells. The Srr-1 protein was shown to interact with a 62-kDa protein in human saliva, which was identified by matrix-assisted laser desorption ionization-time-of-flight analysis as human keratin 4 (K4). Immunoblot and enzyme-linked immunosorbent assay experiments allowed us to narrow down the K4 binding domain in Srr-1 to a region of 157 amino acids (aa). Furthermore, the Srr-1 binding domain of K4 was identified in the C-terminal 255 aa of human K4. Deletion of the srr-1 gene in the genome of S. agalactiae revealed that this gene plays a role in bacterial binding to human K4 and that it is involved in adherence to epithelial HEp-2 cells. Binding to immobilized K4 and adherence to HEp-2 cells were restored by introducing the srr-1 gene on a shuttle plasmid into the srr-1 mutant. Furthermore, incubation of HEp-2 cells with the K4 binding domain of Srr-1 blocked S. agalactiae adherence to epithelial cells in a dose-dependent fashion. This is the first report describing the interaction of a bacterial protein with human K4. PMID:17709412

  14. Streptococcus agalactiae infection in domestic rabbits, Oryctolagus cuniculus.

    PubMed

    Ren, S Y; Geng, Y; Wang, K Y; Zhou, Z Y; Liu, X X; He, M; Peng, X; Wu, C Y; Lai, W M

    2014-12-01

    Streptococcus agalactiae (Group B streptococcus, GBS) has emerged as an important pathogen that affects humans and animals, including aquatic species. In August 2011, a severe infectious disease affecting rabbits, which caused 42% mortality, occurred in Mianyang, Sichuan Province, China. The main clinical signs included acute respiratory distress syndrome, fever, paddling and convulsions. A Gram-positive, chain-forming coccus was isolated from the primary organs and tissues of diseased rabbits and then identified as S. agalactiae by morphology, biochemical and physiological characteristics, 16S rDNA and gyrB gene sequences analysis. All isolates of S. agalactiae showed a similar antibiotic susceptibility, which were sensitive to florfenicol, ampicillin,gentamicin and norfloxacin, as well as being resistant to penicillin, amoxicillin and tetracycline. To our knowledge, this is the first report on S. agalactiae natural infection in domestic rabbits.

  15. Comparative genomics analysis of Streptococcus agalactiae reveals that isolates from cultured tilapia in China are closely related to the human strain A909

    PubMed Central

    2013-01-01

    Background Streptococcus agalactiae, also referred to as Group B Streptococcus (GBS), is a frequent resident of the rectovaginal tract in humans, and a major cause of neonatal infection. In addition, S. agalactiae is a known fish pathogen, which compromises food safety and represents a zoonotic hazard. The complete genome sequence of the piscine S. agalactiae isolate GD201008-001 was compared with 14 other piscine, human and bovine strains to explore their virulence determinants, evolutionary relationships and the genetic basis of host tropism in S. agalactiae. Results The pan-genome of S. agalactiae is open and its size increases with the addition of newly sequenced genomes. The core genes shared by all isolates account for 50 ~ 70% of any single genome. The Chinese piscine isolates GD201008-001 and ZQ0910 are phylogenetically distinct from the Latin American piscine isolates SA20-06 and STIR-CD-17, but are closely related to the human strain A909, in the context of the clustered regularly interspaced short palindromic repeats (CRISPRs), prophage, virulence-associated genes and phylogenetic relationships. We identified a unique 10 kb gene locus in Chinese piscine strains. Conclusions Isolates from cultured tilapia in China have a close genomic relationship with the human strain A909. Our findings provide insight into the pathogenesis and host-associated genome content of piscine S. agalactiae isolated in China. PMID:24215651

  16. 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.

  17. Molecular typing of Streptococcus agalactiae isolates from fish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic variability among Streptococcus agalactiae isolates recovered from fish was characterized using single-stranded conformation polymorphisms (SSCP) analysis of the intergenic spacer region (ISR), and amplified fragment length polymorphism (AFLP) fingerprinting. A total of 49 S. agalactiae ...

  18. Streptococcus agalactiae infection in zebrafish larvae.

    PubMed

    Kim, Brandon J; Hancock, Bryan M; Del Cid, Natasha; Bermudez, Andres; Traver, David; Doran, Kelly S

    2015-02-01

    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

  19. Complete Genome Sequence of Nonhemolytic Streptococcus agalactiae Serotype V Strain 1, Isolated from the Buccal Cavity of a Canine

    PubMed Central

    Harden, Leeanne K.; Morales, Karina M.

    2016-01-01

    The complete genome sequence from a nonhemolytic strain of Streptococcus agalactiae from the oral cavity of a canine was assembled. The genome is 2,165,968 bp, contains 2,055 genes, and is classified as group B streptococcus (GBS) serotype V, strain 1. A comparison to other S. agalactiae sequences shows high gene synteny with human and bovine strains. PMID:26823579

  20. Streptococcus agalactiae pyomyositis in diabetes mellitus.

    PubMed

    Panikkath, Deepa; Tantrachoti, Pakpoom; Panikkath, Ragesh; Nugent, Kenneth

    2016-07-01

    Pyomyositis is an acute infectious disorder affecting the skeletal muscle. Although seen more commonly in the tropics, cases are being reported in temperate countries, including the United States. We report a case of nontropical pyomyositis in a 58-year-old diabetic man who presented with a vague chest wall swelling. His initial clinical presentation and imaging findings suggested an intramuscular hematoma. He later developed fever with increased swelling, and pyomyositis was diagnosed after an aspiration of the swelling yielded Streptococcus agalactiae. Aspiration of the abscess and the use of appropriate antibiotics led to complete resolution of the disease. We discuss possible factors in diabetics that might predispose them to pyomyositis. PMID:27365874

  1. Necrotizing fasciitis in captive juvenile Crocodylus porosus caused by Streptococcus agalactiae: an outbreak and review of the animal and human literature.

    PubMed

    Bishop, E J; Shilton, C; Benedict, S; Kong, F; Gilbert, G L; Gal, D; Godoy, D; Spratt, B G; Currie, B J

    2007-11-01

    We observed an outbreak of necrotizing fasciitis associated with Streptococcus agalactiae infection in a group of juvenile saltwater crocodiles (Crocodylus porosus). We undertook screening of crocodiles and the environment to clarify the source of the outbreak and evaluated the isolates cultured from post-mortem specimens with molecular methods to assess clonality and the presence of known group B streptococcal virulence determinants. The isolates were indistinguishable by pulsed-field gel electrophoresis. They were a typical serotype Ia strain with the Calpha-like protein gene, epsilon (or alp1), the mobile genetic elements IS381 ISSag1 and ISSag2, and belonged to multi-locus sequence type (ST) 23. All of these characteristics suggest they were probably of human origin. We review the medical and veterinary literature relating to S. agalactiae necrotizing fasciitis, epidemiology and virulence determinants.

  2. Phylogenetic relationships among Streptococcus agalactiae isolated from piscine, dolphin, bovine and human sources: a dolphin and piscine lineage associated with a fish epidemic in Kuwait is also associated with human...

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Group B Streptococcus agalactiae (GBS) causes of infections in multiple animals. This study examined the genetic relatedness of piscine, dolphin, and human GBS isolates and bovine GBS reference strains from different geographical regions using serological and multilocus sequence typing (MLST) techni...

  3. Molecular Characterization of Human-Colonizing Streptococcus agalactiae Strains Isolated from Throat, Skin, Anal Margin, and Genital Body Sites▿

    PubMed Central

    van der Mee-Marquet, Nathalie; Fourny, Laure; Arnault, Laurence; Domelier, Anne-Sophie; Salloum, Mazen; Lartigue, Marie-Frédérique; Quentin, Roland

    2008-01-01

    Streptococcus agalactiae carriage was evaluated by sampling four body sites in a group of 249 healthy individuals including both sexes and a wide range of ages; the aims were to study the population structure of colonizing strains by multilocus sequence typing (MLST) and to evaluate their diversity by serotyping, SmaI macrorestriction analysis, and PCR screening for genetic markers of highly virulent clones for neonates. The prevalences of carriage were 27% in women and 32% in men. The major positive body site was the genital tract (23% in women and 21% in men); skin, throats, and anal margins were also positive in 2%, 4%, and 14%, respectively. These human-colonizing strains belonged mostly to serotypes III (24%), Ia (21%), V (18%), and Ib (17%). Twenty-three sequence types (STs) were identified. The MLST characteristics of the strains isolated from a single anatomic site—genital (vagina [women] or from a sample of the first urination after arising from a night's sleep [men]), throat, skin, or anal margin—suggest a body site colonization specificity for particular STs: strains of STs 2, 10, 19, and 196 were isolated only from genital sites; strains of STs 1, 8, and 23 were isolated more frequently from throat florae; and strains recovered only from anal margin samples were more closely related to strains isolated from throats than to those from genital sites. Most strains of STs 1, 8, and 23—STs that are increasingly described as being responsible for adult infections—did not carry any markers of strains virulent for neonates, suggesting that the virulence of these strains is probably associated with other genetic determinants. In addition, the genetic diversities of the strains varied between STs: STs 2, 8, 10, 23, and 196 were the most diverse; STs 1 and 19 were more homogeneous; and ST 17 strains formed three distant groups. PMID:18632904

  4. Distribution of serotypes and evaluation of antimicrobial susceptibility among human and bovine Streptococcus agalactiae strains isolated in Brazil between 1980 and 2006.

    PubMed

    Pinto, Tatiana Castro Abreu; Costa, Natália Silva; Vianna Souza, Aline Rosa; Silva, Ligia Guedes da; Corrêa, Ana Beatriz de Almeida; Fernandes, Flavio Gimenis; Oliveira, Ivi Cristina Menezes; Mattos, Marcos Corrêa de; Rosado, Alexandre Soares; Benchetrit, Leslie Claude

    2013-01-01

    Streptococcus agalactiae is a common agent of clinical and subclinical bovine mastitis and an important cause of human infections, mainly among pregnant women, neonates and nonpregnant adults with underlying diseases. The present study describes the genetic and phenotypic diversity among 392 S. agalactiae human and bovine strains isolated between 1980 and 2006 in Brazil. The most prevalent serotypes were Ia, II, III and V and all the strains were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampicin and tetracycline was observed. Among the erythromycin resistant strains, mefA/E, ermA and, mainly, ermB gene were detected, and a shift of prevalence from the macrolide resistance phenotype to the macrolide-lincosamide-streptogramin B resistance phenotype over the years was observed. The 23 macrolide-resistant strains showed 19 different pulsed-field gel electrophoresis profiles. Regarding macrolide resistance, a major concern in S. agalactiae epidemiology, the present study describes an increase in erythromycin resistance from the 80s to the 90s followed by a decrease in the 2000-2006 period. Also, the genetic heterogeneity described points out that erythromycin resistance in Brazil is rather due to horizontal gene transmission than to spreading of specific macrolide-resistant clones. PMID:23453948

  5. Multiple Evolutionary Selections Involved in Synonymous Codon Usages in the Streptococcus agalactiae Genome

    PubMed Central

    Ma, Yan-Ping; Ke, Hao; Liang, Zhi-Ling; Liu, Zhen-Xing; Hao, Le; Ma, Jiang-Yao; Li, Yu-Gu

    2016-01-01

    Streptococcus agalactiae is an important human and animal pathogen. To better understand the genetic features and evolution of S. agalactiae, multiple factors influencing synonymous codon usage patterns in S. agalactiae were analyzed in this study. A- and U-ending rich codons were used in S. agalactiae function genes through the overall codon usage analysis, indicating that Adenine (A)/Thymine (T) compositional constraints might contribute an important role to the synonymous codon usage pattern. The GC3% against the effective number of codon (ENC) value suggested that translational selection was the important factor for codon bias in the microorganism. Principal component analysis (PCA) showed that (i) mutational pressure was the most important factor in shaping codon usage of all open reading frames (ORFs) in the S. agalactiae genome; (ii) strand specific mutational bias was not capable of influencing the codon usage bias in the leading and lagging strands; and (iii) gene length was not the important factor in synonymous codon usage pattern in this organism. Additionally, the high correlation between tRNA adaptation index (tAI) value and codon adaptation index (CAI), frequency of optimal codons (Fop) value, reinforced the role of natural selection for efficient translation in S. agalactiae. Comparison of synonymous codon usage pattern between S. agalactiae and susceptible hosts (human and tilapia) showed that synonymous codon usage of S. agalactiae was independent of the synonymous codon usage of susceptible hosts. The study of codon usage in S. agalactiae may provide evidence about the molecular evolution of the bacterium and a greater understanding of evolutionary relationships between S. agalactiae and its hosts. PMID:26927064

  6. A selective-differential medium for detection of Streptococcus agalactiae.

    PubMed

    Guthrie, R K; Brunson, K W; Stiles, J C

    1968-01-01

    A practical culture medium which allows direct plating of milk samples for detection and differentiation of Streptococcus agalactiae within 48 hours is described. Most other micro-organisms likely to be present in these samples are inhibited. Although some strains of Staphylococcus species and ofStreptococcus faecalis are able to grow, they may be differentiated on the basis of reaction in the medium surrounding the colonies.

  7. Pigment Production by Streptococcus agalactiae in Quasi-Defined Media

    PubMed Central

    Rosa-Fraile, Manuel; Sampedro, Antonio; Rodríguez-Granger, Javier; García-Peña, Maria Luisa; Ruiz-Bravo, Alfonso; Haïdour, Ali

    2001-01-01

    A quasi-defined medium that supports the growth of Streptococcus agalactiae as pigmented colonies has been developed. The medium contains starch, a peptic digest of albumin, amino acids, nucleosides, vitamins, and salts. The presence of free cysteine, which could be replaced with other sulphur-containing compounds and to a lesser degree by reducing agents, was required for pigment formation. PMID:11133484

  8. Comparison of Z and R3 antigen expression and of genes encoding other antigenic markers in invasive human and bovine Streptococcus agalactiae strains from Norway.

    PubMed

    Maeland, Johan A; Radtke, Andreas

    2013-12-27

    Streptococcus agalactiae (GBS) may cause a variety of infectious diseases in humans caused by human GBS and mastitis in cattle caused by bovine GBS. Over the last few years molecular testing has provided evidence that human and bovine GBS have evolved along diverse phylogenetic lines. In the present study 173 invasive human GBS strains and 52 invasive bovine strains were tested for altogether 18 strain-variable and surface-localized antigenic markers including all 10 capsular polysaccharides (CPS) and proteins including Cβ, the alpha-like proteins, R3 and the recently described Z1 and Z2 antigens. PCR was used to detect encoding genes and antibody-based methods to detect expression of antigens. Thirteen of the 18 markers were detected in isolates of both strain categories. Seven of the ten CPS antigens were detected in both groups with types III and V predominating in the human GBS strains, types IV and V in the bovine isolates. Z1, Z2 and/or R3 expression and the genes encoding Cβ, Cα, Alp1, Alp2/3 or R4 (Rib) were detected in both groups. Protein antigen-CPS associations well known for human strains were essentially the same in the bovine isolates. The results show that in spite of evolution along different lines, human and bovine GBS share a variety of surface-exposed antigenic markers, substantiating close relationship between the two GBS subpopulations. PMID:24120184

  9. Antibacterial activity and mechanism of berberine against Streptococcus agalactiae

    PubMed Central

    Peng, Lianci; Kang, Shuai; Yin, Zhongqiong; Jia, Renyong; Song, Xu; Li, Li; Li, Zhengwen; Zou, Yuanfeng; Liang, Xiaoxia; Li, Lixia; He, Changliang; Ye, Gang; Yin, Lizi; Shi, Fei; Lv, Cheng; Jing, Bo

    2015-01-01

    The antibacterial activity and mechanism of berberine against Streptococcus agalactiae were investigated in this study by analyzing the growth, morphology and protein of the S. agalactiae cells treated with berberine. The antibacterial susceptibility test result indicated minimum inhibition concentration (MIC) of berberine against Streptococcus agalactiae was 78 μg/mL and the time-kill curves showed the correlation of concentration-time. After the bacteria was exposed to 78 μg/mL berberine, the fragmentary cell membrane and cells unequal division were observed by the transmission electron microscopy (TEM), indicating the bacterial cells were severely damaged. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) study demonstrated that berberine could damage bacterial cells through destroying cellular proteins. Meanwhile, Fluorescence microscope revealed that berberine could affect the synthesis of DNA. In conclusion, these results strongly suggested that berberine may damage the structure of bacterial cell membrane and inhibit synthesis of protein and DNA, which cause Streptococcus agalactiae bacteria to die eventually. PMID:26191220

  10. Antibacterial activity and mechanism of berberine against Streptococcus agalactiae.

    PubMed

    Peng, Lianci; Kang, Shuai; Yin, Zhongqiong; Jia, Renyong; Song, Xu; Li, Li; Li, Zhengwen; Zou, Yuanfeng; Liang, Xiaoxia; Li, Lixia; He, Changliang; Ye, Gang; Yin, Lizi; Shi, Fei; Lv, Cheng; Jing, Bo

    2015-01-01

    The antibacterial activity and mechanism of berberine against Streptococcus agalactiae were investigated in this study by analyzing the growth, morphology and protein of the S. agalactiae cells treated with berberine. The antibacterial susceptibility test result indicated minimum inhibition concentration (MIC) of berberine against Streptococcus agalactiae was 78 μg/mL and the time-kill curves showed the correlation of concentration-time. After the bacteria was exposed to 78 μg/mL berberine, the fragmentary cell membrane and cells unequal division were observed by the transmission electron microscopy (TEM), indicating the bacterial cells were severely damaged. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) study demonstrated that berberine could damage bacterial cells through destroying cellular proteins. Meanwhile, Fluorescence microscope revealed that berberine could affect the synthesis of DNA. In conclusion, these results strongly suggested that berberine may damage the structure of bacterial cell membrane and inhibit synthesis of protein and DNA, which cause Streptococcus agalactiae bacteria to die eventually.

  11. Antibiotic resistance of Streptococcus agalactiae from cows with mastitis.

    PubMed

    Gao, Jian; Yu, Fu-Qing; Luo, Li-Ping; He, Jian-Zhong; Hou, Rong-Guang; Zhang, Han-Qi; Li, Shu-Mei; Su, Jing-Liang; Han, Bo

    2012-12-01

    The aim of this study was to characterise the phenotypic and genotypic antibiotic resistance patterns of Streptococcus agalactiae isolated from cows with mastitis in China. Antibiotic resistance was based on minimum inhibitory concentrations and detection of resistance genes by PCR. S. agalactiae isolates most frequently exhibited phenotypic resistance to tetracycline, while the resistance genes most frequently detected were ermB, tetL and tetM. Resistance genes were detected in some susceptible isolates, whereas no resistance genes could be detected in some resistant isolates, indicating that the resistance genotype does not accurately predict phenotypic resistance. PMID:22627045

  12. 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.

  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. Protein degradation in bovine milk caused by Streptococcus agalactiae.

    PubMed

    Åkerstedt, Maria; Wredle, Ewa; Lam, Vo; Johansson, Monika

    2012-08-01

    Streptococcus (Str.) agalactiae is a contagious mastitis bacterium, often associated with cases of subclinical mastitis. Different mastitis bacteria have been evaluated previously from a diagnostic point of view, but there is a lack of knowledge concerning their effect on milk composition. Protein composition is important in achieving optimal yield and texture when milk is processed to fermented products, such as cheese and yoghurt, and is thus of great economic value. The aim of this in vitro study was to evaluate protein degradation mainly caused by exogenous proteases originating from naturally occurring Str. agalactiae. The samples were incubated at 37°C to imitate degradation caused by the bacteria in the udder. Protein degradation caused by different strains of Str. agalactiae was also investigated. Protein degradation was observed to occur when Str. agalactiae was added to milk, but there were variations between strains of the bacteria. Caseins, the most economically important proteins in milk, were degraded up to 75% in milk inoculated with Str. agalactiae in relation to sterile ultra-high temperature (UHT) milk, used as control milk. The major whey proteins, α-lactalbumin and β-lactoglobulin, were degraded up to 21% in relation to the sterile control milk. These results suggest that different mastitis bacteria but also different strains of mastitis bacteria should be evaluated from a milk quality perspective to gain knowledge about their ability to degrade the economically important proteins in milk. PMID:22850579

  15. Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

    PubMed

    Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

    2015-10-22

    Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions. PMID:26255553

  16. Skizzle Is a Novel Plasminogen- and Plasmin-binding Protein from Streptococcus agalactiae That Targets Proteins of Human Fibrinolysis to Promote Plasmin Generation*

    PubMed Central

    Wiles, Karen G.; Panizzi, Peter; Kroh, Heather K.; Bock, Paul E.

    2010-01-01

    Skizzle (SkzL), secreted by Streptococcus agalactiae, has moderate sequence identity to streptokinase and staphylokinase, bacterial activators of human plasminogen (Pg). SkzL binds [Glu]Pg with low affinity (KD 3–16 μm) and [Lys]Pg and plasmin (Pm) with indistinguishable high affinity (KD 80 and 50 nm, respectively). Binding of SkzL to Pg and Pm is completely lysine-binding site-dependent, as shown by the effect of the lysine analog, 6-aminohexanoic acid. Deletion of the COOH-terminal SkzL Lys415 residue reduces affinity for [Lys]Pg and active site-blocked Pm 30-fold, implicating Lys415 in a lysine-binding site interaction with a Pg/Pm kringle. SkzL binding to active site fluorescein-labeled Pg/Pm analogs demonstrates distinct high and low affinity interactions. High affinity binding is mediated by Lys415, whereas the source of low affinity binding is unknown. SkzL enhances the activation of [Glu]Pg by urokinase (uPA) ∼20-fold, to a maximum rate indistinguishable from that for [Lys]Pg and [Glu]Pg activation in the presence of 6-aminohexanoic acid. SkzL binds preferentially to the partially extended β-conformation of [Glu]Pg, which is in unfavorable equilibrium with the compact α-conformation, thereby converting [Glu]Pg to the fully extended γ-conformation and accelerating the rate of its activation by uPA. SkzL enhances [Lys]Pg and [Glu]Pg activation by single-chain tissue-type Pg activator, ∼42- and ∼650-fold, respectively. SkzL increases the rate of plasma clot lysis by uPA and single-chain tissue-type Pg activator ∼2-fold, confirming its cofactor activity in a physiological model system. The results suggest a role for SkzL in S. agalactiae pathogenesis through fibrinolytic enhancement. PMID:20435890

  17. Comparative genomics and the role of lateral gene transfer in the evolution of bovine adapted Streptococcus agalactiae.

    PubMed

    Richards, Vincent P; Lang, Ping; Bitar, Paulina D Pavinski; Lefébure, Tristan; Schukken, Ynte H; Zadoks, Ruth N; Stanhope, Michael J

    2011-08-01

    In addition to causing severe invasive infections in humans, Streptococcus agalactiae, or group B Streptococcus (GBS), is also a major cause of bovine mastitis. Here we provide the first genome sequence for S. agalactiae isolated from a cow diagnosed with clinical mastitis (strain FSL S3-026). Comparison to eight S. agalactiae genomes obtained from human disease isolates revealed 183 genes specific to the bovine strain. Subsequent polymerase chain reaction (PCR) screening for the presence/absence of a subset of these loci in additional bovine and human strains revealed strong differentiation between the two groups (Fisher exact test: p<0.0001). The majority of the bovine strain-specific genes (∼ 85%) clustered tightly into eight genomic islands, suggesting these genes were acquired through lateral gene transfer (LGT). This bovine GBS also contained an unusually high proportion of insertion sequences (4.3% of the total genome), suggesting frequent genomic rearrangement. Comparison to other mastitis-causing species of bacteria provided strong evidence for two cases of interspecies LGT within the shared bovine environment: bovine S. agalactiae with Streptococcus uberis (nisin U operon) and Streptococcus dysgalactiae subsp. dysgalactiae (lactose operon). We also found evidence for LGT, involving the salivaricin operon, between the bovine S. agalactiae strain and either Streptococcus pyogenes or Streptococcus salivarius. Our findings provide insight into mechanisms facilitating environmental adaptation and acquisition of potential virulence factors, while highlighting both the key role LGT has played in the recent evolution of the bovine S. agalactiae strain, and the importance of LGT among pathogens within a shared environment. PMID:21536150

  18. Comparative genomics and the role of lateral gene transfer in the evolution of bovine adapted Streptococcus agalactiae.

    PubMed

    Richards, Vincent P; Lang, Ping; Bitar, Paulina D Pavinski; Lefébure, Tristan; Schukken, Ynte H; Zadoks, Ruth N; Stanhope, Michael J

    2011-08-01

    In addition to causing severe invasive infections in humans, Streptococcus agalactiae, or group B Streptococcus (GBS), is also a major cause of bovine mastitis. Here we provide the first genome sequence for S. agalactiae isolated from a cow diagnosed with clinical mastitis (strain FSL S3-026). Comparison to eight S. agalactiae genomes obtained from human disease isolates revealed 183 genes specific to the bovine strain. Subsequent polymerase chain reaction (PCR) screening for the presence/absence of a subset of these loci in additional bovine and human strains revealed strong differentiation between the two groups (Fisher exact test: p<0.0001). The majority of the bovine strain-specific genes (∼ 85%) clustered tightly into eight genomic islands, suggesting these genes were acquired through lateral gene transfer (LGT). This bovine GBS also contained an unusually high proportion of insertion sequences (4.3% of the total genome), suggesting frequent genomic rearrangement. Comparison to other mastitis-causing species of bacteria provided strong evidence for two cases of interspecies LGT within the shared bovine environment: bovine S. agalactiae with Streptococcus uberis (nisin U operon) and Streptococcus dysgalactiae subsp. dysgalactiae (lactose operon). We also found evidence for LGT, involving the salivaricin operon, between the bovine S. agalactiae strain and either Streptococcus pyogenes or Streptococcus salivarius. Our findings provide insight into mechanisms facilitating environmental adaptation and acquisition of potential virulence factors, while highlighting both the key role LGT has played in the recent evolution of the bovine S. agalactiae strain, and the importance of LGT among pathogens within a shared environment.

  19. Characterization of Afb, a novel bifunctional protein in Streptococcus agalactiae

    PubMed Central

    Dehbashi, Sanaz; Pourmand, Mohammad Reza; Mashhadi, Rahil

    2016-01-01

    Background and Objectives: Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in newborns and results in pneumonia and bacteremia in adults. A number of S. agalactiae components are involved in colonization of target cells. Destruction of peptidoglycan and division of covalently linked daughter cells is mediated by autolysins. In this study, autolytic activity and plasma binding ability of AFb novel recombinant protein of S. agalactiae was investigated. Materials and Methods: The gbs1805 gene was cloned and expressed. E. coli strains DH5α and BL21 were used as cloning and expression hosts, respectively. After purification, antigenicity and binding ability to plasma proteins of the recombinant protein was evaluated. Results: AFb, the 18KDa protein was purified successfully. The insoluble mature protein revealed the ability to bind to fibrinogen and fibronectin. This insoluble mature protein revealed that it has the ability to bind to fibrinogen and fibronectin plasma proteins. Furthermore, in silico analysis demonstrated the AFb has an autolytic activity. Conclusions: AFb is a novel protein capable of binding to fibrinogen and fibronectin. This findings lay a ground work for further investigation of the role of the bacteria in adhesion and colonization to the host. PMID:27092228

  20. Comparative analysis of the localization of lipoteichoic acid in Streptococcus agalactiae and Streptococcus pyogenes.

    PubMed Central

    Mattingly, S J; Johnston, B P

    1987-01-01

    The cellular locations of deacylated lipoteichoic acid (dLTA) and lipoteichoic acid (LTA) were examined in late-exponential-phase cells of a serotype III strain of Streptococcus agalactiae (group B streptococci [GBS]) isolated from an infant with late-onset meningitis and compared with a fresh clinical isolate of Streptococcus pyogenes (group A streptococci [GAS]). LTA and dLTA were found to be associated with the protoplast membranes of both organisms, with only dLTA found in mutanolysin cell wall digests. Both organisms released dLTA during growth, but only the GAS released substantial levels of LTA into the culture medium. However, penicillin treatment (5 micrograms/ml for 60 min) of GBS resulted in the recovery of LTA in cell wall digests as well as in the culture medium. These results suggest that under normal growth conditions, the hydrophobic region (glycolipid) of LTA remains associated with the cytoplasmic membrane of GBS and unavailable for hydrophobic interactions at the cell surface with epithelial cells. In contrast, release of LTA into the environment by the GAS allows the fatty acid moieties to interact with hydrophobic domains on the surface of epithelial cells. These results may help explain the marked differences in the specificity of binding between these two major streptococcal pathogens for human fetal and adult epithelial cells. PMID:3308704

  1. Evaluation of nine teat dip formulations under experimental challenge to staphylococcus aureus and streptococcus agalactiae.

    PubMed

    Pankey, J W; Philpot, W N; Boddie, R L; Watts, J L

    1983-01-01

    Nine postmilking teat dips were evaluated by an experimental challenge model against either Staphylococcus aureus, Streptococcus agalactiae, or both. Formulations containing .9 and .6% sodium hypochlorite, 1% sodium dichloro-s-triazene-trione, .55% chlorhexidine gluconate, and .35% povidone iodine reduced incidence of Staphylococcus aureus infections 56.8, 28.3, 75.9, 92.5, and 77.9%. Incidence of infections with Streptococcus agalactiae was reduced 48.1 and 63.2% by 1.7 and 1% sodium dichloro-s-triazene-trione formulations. The 1% chlorhexidine gluconate and .35% povidone iodine products reduced Streptococcus agalactiae infections 71.0 and 67.0%. Three experimental 1% iodophor formulations reduced Streptococcus agalactiae infections 28.9, 44.8, and 50.7%. The experimental challenge model was refined further and provided an efficient method to determine efficacy of postmilking teat dips. PMID:6339575

  2. Transcriptomic and genomic evidence for Streptococcus agalactiae adaptation to the bovine environment

    PubMed Central

    2013-01-01

    Background Streptococcus agalactiae is a major cause of bovine mastitis, which is the dominant health disorder affecting milk production within the dairy industry and is responsible for substantial financial losses to the industry worldwide. However, there is considerable evidence for host adaptation (ecotypes) within S. agalactiae, with both bovine and human sourced isolates showing a high degree of distinctiveness, suggesting differing ability to cause mastitis. Here, we (i) generate RNAseq data from three S. agalactiae isolates (two putative bovine adapted and one human) and (ii) compare publicly available whole genome shotgun sequence data from an additional 202 isolates, obtained from six host species, to elucidate possible genetic factors/adaptations likely important for S. agalactiae growth and survival in the bovine mammary gland. Results Tests for differential expression showed distinct expression profiles for the three isolates when grown in bovine milk. A key finding for the two putatively bovine adapted isolates was the up regulation of a lactose metabolism operon (Lac.2) that was strongly correlated with the bovine environment (all 36 bovine sourced isolates on GenBank possessed the operon, in contrast to only 8/151 human sourced isolates). Multi locus sequence typing of all genome sequences and phylogenetic analysis using conserved operon genes from 44 S. agalactiae isolates and 16 additional Streptococcus species provided strong evidence for acquisition of the operon via multiple lateral gene transfer events, with all Streptococcus species known to be major causes of mastitis, identified as possible donors. Furthermore, lactose fermentation tests were only positive for isolates possessing Lac.2. Combined, these findings suggest that lactose metabolism is likely an important adaptation to the bovine environment. Additional up regulation in the bovine adapted isolates included genes involved in copper homeostasis, metabolism of purine, pyrimidine

  3. Non-infectivity of Cattle Streptococcus agalactiae in Nile Tilapia, Oreochromis niloticus and Channel Catfish, Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae is classified as a Lancefield’s group B Streptococcus (GBS). It is the causative bacterium of streptococcosis that is responsible for severe economic losses in wild and cultured fish, worldwide. Streptococcus agalactiae also causes bovine mastitis. Only limited comparativ...

  4. Streptococcus agalactiae mural infective endocarditis in a structurally normal heart.

    PubMed

    Ariyoshi, Nobuhiro; Miyamoto, Keisuke; Bolger, Dennis T

    2016-01-01

    A 38-year-old Caucasian man with uncontrolled diabetes mellitus type 2 was admitted with a 1-week duration of fevers, chills, and a non-productive cough. He had a left ischiorectal abscess 1 month prior to admission. Physical examination revealed caries on a left upper molar and a well-healed scar on the left buttock, but no heart murmur or evidence of micro-emboli. Blood cultures grew Streptococcus agalactiae. A transesophageal echocardiogram revealed a mobile mass in the right ventricle that attached to chordae tendineae without valvular disease or dysfunction. A computed tomography (CT) with contrast revealed the mass within the right ventricle, a left lung cavitary lesion, and a splenic infarction. He was initially treated with penicillin G for a week. Subsequently, ceftriaxone was continued for a total of 8 weeks. A follow-up CT showed no evidence of right ventricular mass 8 weeks after discharge. This is the first reported case of S. agalactiae mural infective endocarditis in a structurally normal heart. PMID:27124171

  5. Streptococcus agalactiae mural infective endocarditis in a structurally normal heart

    PubMed Central

    Ariyoshi, Nobuhiro; Miyamoto, Keisuke; Bolger, Dennis T.

    2016-01-01

    A 38-year-old Caucasian man with uncontrolled diabetes mellitus type 2 was admitted with a 1-week duration of fevers, chills, and a non-productive cough. He had a left ischiorectal abscess 1 month prior to admission. Physical examination revealed caries on a left upper molar and a well-healed scar on the left buttock, but no heart murmur or evidence of micro-emboli. Blood cultures grew Streptococcus agalactiae. A transesophageal echocardiogram revealed a mobile mass in the right ventricle that attached to chordae tendineae without valvular disease or dysfunction. A computed tomography (CT) with contrast revealed the mass within the right ventricle, a left lung cavitary lesion, and a splenic infarction. He was initially treated with penicillin G for a week. Subsequently, ceftriaxone was continued for a total of 8 weeks. A follow-up CT showed no evidence of right ventricular mass 8 weeks after discharge. This is the first reported case of S. agalactiae mural infective endocarditis in a structurally normal heart. PMID:27124171

  6. Genomic comparison of virulent and non-virulent Streptococcus agalactiae in fish.

    PubMed

    Delannoy, C M J; Zadoks, R N; Crumlish, M; Rodgers, D; Lainson, F A; Ferguson, H W; Turnbull, J; Fontaine, M C

    2016-01-01

    Streptococcus agalactiae infections in fish are predominantly caused by beta-haemolytic strains of clonal complex (CC) 7, notably its namesake sequence type (ST) 7, or by non-haemolytic strains of CC552, including the globally distributed ST260. In contrast, CC23, including its namesake ST23, has been associated with a wide homeothermic and poikilothermic host range, but never with fish. The aim of this study was to determine whether ST23 is virulent in fish and to identify genomic markers of fish adaptation of S. agalactiae. Intraperitoneal challenge of Nile tilapia, Oreochromis niloticus (Linnaeus), showed that ST260 is lethal at doses down to 10(2) cfu per fish, whereas ST23 does not cause disease at 10(7) cfu per fish. Comparison of the genome sequence of ST260 and ST23 with those of strains derived from fish, cattle and humans revealed the presence of genomic elements that are unique to subpopulations of S. agalactiae that have the ability to infect fish (CC7 and CC552). These loci occurred in clusters exhibiting typical signatures of mobile genetic elements. PCR-based screening of a collection of isolates from multiple host species confirmed the association of selected genes with fish-derived strains. Several fish-associated genes encode proteins that potentially provide fitness in the aquatic environment. PMID:25399660

  7. Capsular gene typing of Streptococcus agalactiae compared to serotyping by latex agglutination.

    PubMed

    Yao, Kaihu; Poulsen, Knud; Maione, Domenico; Rinaudo, C Daniela; Baldassarri, Lucilla; Telford, John L; Sørensen, Uffe B Skov; Kilian, Mogens

    2013-02-01

    We evaluated three different PCR-based capsular gene typing methods applied to 312 human and bovine Streptococcus agalactiae (group B Streptococcus [GBS]) isolates and compared the results to serotyping results obtained by latex agglutination. Among 281 human isolates 27% could not be typed by latex agglutination. All 312 isolates except 5 could be typed by the three PCR methods combined. Two of these methods were multiplex assays. Among the isolates that were typeable by both latex agglutination and capsular gene typing, 94% showed agreement between the two methods. However, each of the PCR methods showed limitations. One of the methods did not include all 10 recognized serotypes, one misidentified eight isolates of serotypes Ib and IV as serotype Ia, and one did not distinguish between serotypes VII and IX. For five isolates that showed aberrant patterns in the capsular gene typing, long-range PCR targeting the cps operon disclosed large insertions or deletions affecting the cps gene cluster. A sensitive flow cytometric assay based on serotype-specific antibodies applied to 76 selected isolates that were nontypeable by latex agglutination revealed that approximately one-half of these did express capsular polysaccharide. A procedure for convenient and reliable capsular gene typing to be included in epidemiological and surveillance studies of S. agalactiae is proposed. PMID:23196363

  8. Rga is a regulator of adherence and pilus formation in Streptococcus agalactiae.

    PubMed

    Samen, Ulrike; Heinz, Beate; Boisvert, Heike; Eikmanns, Bernhard J; Reinscheid, Dieter J; Borges, Frédéric

    2011-08-01

    Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in neonates and is also the causative agent of several serious infections in immunocompromised adults. S. agalactiae encounters multiple niches during an infection, suggesting that regulatory mechanisms control the expression of specific virulence factors in this bacterium. The present study describes the functional characterization of a gene from S. agalactiae, designated rga, which encodes a protein with significant similarity to members of the RofA-like protein (RALP) family of transcriptional regulators. After deletion of the rga gene in the genome of S. agalactiae, the mutant strain exhibited significantly reduced expression of the genes srr-1 and pilA, which encode a serine-rich repeat surface glycoprotein and a pilus protein, respectively, and moderately increased expression of the fbsA gene, which encodes a fibrinogen-binding protein. Electrophoretic mobility shift assays demonstrated specific DNA binding of purified Rga to the promoter regions of pilA and fbsA, suggesting that Rga directly controls pilA and fbsA. Adherence assays revealed significantly reduced binding of the Δrga mutant to epithelial HEp-2 cells and to immobilized human keratin 4, respectively. In contrast, the adherence of the Δrga mutant to A549 cells and its binding to human fibrinogen was significantly increased. Immunoblot and immunoelectron microscopy revealed that the quantity of pilus structures was significantly reduced in the Δrga mutant compared with the parental strain. The wild-type phenotype could be restored by plasmid-mediated expression of rga, demonstrating that the mutant phenotypes resulted from a loss of Rga function.

  9. An unusual case of Streptococcus agalactiae meningitis in a patient with sys-temic lupus erythematosus

    PubMed Central

    Protonotariou, E; Arampatzi, A; Ourailoglou, V; Diza, E; Skoura, L

    2015-01-01

    Background: Streptococcus agalactiae (group B Streptococcus) is a major cause of sepsis and meningitis in neonates and an important cause of invasive disease in adults. Case description: We describe an unusual case of fatal bacterial meningitis caused by Streptococcus agalactiae in a young man suffering from systemic lupus erythematosus for over 20 years. The young man was transferred intubated in AHEPA University Hospital in a coma; twenty-four hours upon arrival and despite intense invasive treatment, he died from multiple organ failure. Conclusion: The risk of serious infections in patients with systemic lupus erythematosus even under treatment with moderate doses of corticosteroids is high. Hippokratia 2015; 19 (4):372-373.

  10. 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.

  11. 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

  12. Streptococcus agalactiae Serotype Distribution and Antimicrobial Susceptibility in Pregnant Women in Gabon, Central Africa.

    PubMed

    Belard, Sabine; Toepfner, Nicole; Capan-Melser, Mesküre; Mombo-Ngoma, Ghyslain; Zoleko-Manego, Rella; Groger, Mirjam; Matsiegui, Pierre-Blaise; Agnandji, Selidji T; Adegnika, Ayôla A; González, Raquel; Kremsner, Peter G; Menendez, Clara; Ramharter, Michael; Berner, Reinhard

    2015-11-25

    Neonatal invasive disease due to Streptococcus agalactiae is life threatening and preventive strategies suitable for resource limited settings are urgently needed. Protective coverage of vaccine candidates based on capsular epitopes will relate to local epidemiology of S. agalactiae serotypes and successful management of critical infections depends on timely therapy with effective antibiotics. This is the first report on serotype distribution and antimicrobial susceptibility of S. agalactiae in pregnant women from a Central African region. Serotypes V, III, and Ib accounted for 88/109 (81%) serotypes and all isolates were susceptible to penicillin and clindamycin while 13% showed intermediate susceptibility to erythromycin.

  13. Identification of a novel insertion sequence element in Streptococcus agalactiae. bspeller@imib.rwth-aachen.de.

    PubMed

    Spellerberg, B; Martin, S; Franken, C; Berner, R; Lütticken, R

    2000-01-01

    Gain and loss of bacterial pathogenicity is often associated with mobile genetic elements. A novel insertion sequence (IS) element designated ISSa4 was identified in Streptococcus agalactiae (group B streptococci). The 963bp IS element is flanked by 25bp perfect inverted repeats and led to the duplication of a 9bp target sequence at the insertion site. ISSa4 contains one open reading frame coding for a putative transposase of 287 aa and exhibits closest similarities to insertion elements of the IS982 family which has previously not been identified in streptococci. Analysis of different S. agalactiae strains showed that the copy number of ISSa4 in S. agalactiae varies significantly between strains. The S. agalactiae strain with the highest copy number of ISSa4 was nonhemolytic and harbored one copy inserted in cylB, which encodes the membrane-spanning domain of the putative hemolysin transporter (Spellerberg et al., 1999. Identification of genetic determinants for the hemolytic activity of Streptococcus agalactiae by ISS1 transposition. J. Bacteriol. 181, 3212-3219). Determination of the distribution of ISSa4 in different S. agalactiae strains revealed that ISSa4 could be detected only in strains isolated after 1996, which might indicate a recent acquisition of this novel insertion element by S. agalactiae.

  14. [Streptococcus agalactiae (GBS)--the characteristic of isolated strains from productive women's vagina].

    PubMed

    Wolny, Katarzyna; Gołda-Matuszak, Ewa

    2010-01-01

    The main aim of my research: to determine the frequency of colonisation Streptococcus agalactiae from productive women's vagina, an evaluation of usefulness microbiological diagnostic methods to detect GBS, to define serotype of analysed strains of S. agalactiae. After all, I tried to define fenotypic differential, biochemical and antimicrobial susceptibility between GBS with and without hemolysis. All of strains S. agalactiae (n = 380) belong to bacteria Gram(+), they had B serologic group and didn't produce catalase. On the basis of TSA+5% sheep blood streptococcus with beta-hemolysis grew like a small, grey and shiny colonies with a narrow, bright ring. On the same base we had S. agalactiae without beta-hemolysis, in examine material--6% (n = 22). On the basis of Strepto B ID S. agalactiae grew like a small, round red colonies and on the base Granada agar like an orange, white colonies. The level of colonisation S. agalactiae was 22% (380GBS/1727women). Identification of analysed strains of S. agalactiae was made by test API 20 Strep. The susceptibility was examined to ampicilin, azithromycin, erythromycin, clindamycin, chloramphenicol, doxycyclin, cotrimoxasol, ciprofloxacin. Serotypes III (50%), Ia (18%) and V (14%) prevailed. PMID:20873487

  15. Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production.

    PubMed

    Vasilyeva, Anastasia; Santos Sanches, Ilda; Florindo, Carlos; Dmitriev, Alexander

    2015-01-01

    Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level. Inactivation of bgrR abrogated bac gene expression and increased virulence properties of S. agalactiae. In this study, a total of 140 strains were screened for the presence of bac gene, and the TCS bgrR and bgrS genes. A total of 53 strains carried the bac, bgrR and bgrS genes. Most of them (48 strains) expressed β antigen, while five strains did not express β antigen. Three strains, in which bac gene sequence was intact, while bgrR and/or bgrS genes had mutations, and expression of β antigen was absent, were complemented with a constructed plasmid pBgrRS(P) encoding functionally active bgrR and bgrS gene alleles. This procedure restored expression of β antigen indicating the crucial regulatory role of TCS BgrRS. The complemented strain A49V/BgrRS demonstrated attenuated virulence in intraperitoneal mice model of S. agalactiae infection compared to parental strain A49V. In conclusion we showed that disruption of β antigen expression is associated with: i) insertion of ISSa4 upstream the bac gene just after the ribosomal binding site; ii) point mutation G342A resulting a stop codon TGA within the bac gene and a truncated form of β antigen; iii) single deletion (G) in position 439 of the bgrR gene resulting in a frameshift and the loss of DNA-binding domain of the BgrR protein, and iv) single base substitutions in bgrR and bgrS genes causing single amino acid substitutions in BgrR (Arg187Lys) and BgrS (Arg252Gln). The fact that BgrRS negatively controls virulent properties of S. agalactiae gives a novel clue for understanding of S

  16. Recombination between Streptococcus suis ICESsu32457 and Streptococcus agalactiae ICESa2603 yields a hybrid ICE transferable to Streptococcus pyogenes.

    PubMed

    Marini, Emanuela; Palmieri, Claudio; Magi, Gloria; Facinelli, Bruna

    2015-07-01

    Integrative conjugative elements (ICEs) are mobile genetic elements that reside in the chromosome but retain the ability to undergo excision and to transfer by conjugation. Genes involved in drug resistance, virulence, or niche adaptation are often found among backbone genes as cargo DNA. We recently characterized in Streptococcus suis an ICE (ICESsu32457) carrying resistance genes [tet(O/W/32/O), tet(40), erm(B), aphA, and aadE] in the 15K unstable genetic element, which is flanked by two ∼1.3kb direct repeats. Remarkably, ∼1.3-kb sequences are conserved in ICESa2603 of Streptococcus agalactiae 2603V/R, which carry heavy metal resistance genes cadC/cadA and mer. In matings between S. suis 32457 (donor) and S. agalactiae 2603V/R (recipient), transconjugants were obtained. PCR experiments, PFGE, and sequence analysis of transconjugants demonstrated a tandem array between ICESsu32457 and ICESa2603. Matings between tandem array-containing S. agalactiae 2603V/R (donor) and Streptococcus pyogenes RF12 (recipient) yielded a single transconjugant containing a hybrid ICE, here named ICESa2603/ICESsu32457. The hybrid formed by recombination of the left ∼1.3-kb sequence of ICESsu32457 and the ∼1.3-kb sequence of ICESa2603. Interestingly, the hybrid ICE was transferable between S. pyogenes strains, thus demonstrating that it behaves as a conventional ICE. These findings suggest that both tandem arrays and hybrid ICEs may contribute to the evolution of antibiotic resistance in streptococci, creating novel mobile elements capable of disseminating new combinations of antibiotic resistance genes.

  17. Comparative proteome analysis of two Streptococcus agalactiae strains from cultured tilapia with different virulence.

    PubMed

    Li, Wei; Su, You-Lu; Mai, Yong-Zhan; Li, Yan-Wei; Mo, Ze-Quan; Li, An-Xing

    2014-05-14

    Streptococcus agalactiae is a major piscine pathogen, which causes significant morbidity and mortality among numerous fish species, and results in huge economic losses to aquaculture. Many S. agalactiae strains showing different virulence characteristics have been isolated from infected tilapia in different geographical regions throughout South China in the recent years, including natural attenuated S. agalactiae strain TFJ0901 and virulent S. agalactiae strain THN0901. In the present study, survival of tilapia challenged with S. agalactiae strain TFJ0901 and THN0901 (10(7)CFU/fish) were 93.3% and 13.3%, respectively. Moreover, there are severe lesions of the examined tissues in tilapia infected with strain THN0901, but no significant histopathological changes were observed in tilapia infected with the strain TFJ0901. In order to elucidate the factors responsible for the invasive potential of S. agalactiae between two strains TFJ0901 and THN0901, a comparative proteome analysis was applied to identify the different protein expression profiles between the two strains. 506 and 508 cellular protein spots of S. agalactiae TFJ0901 and THN0901 were separated by two dimensional electrophoresis, respectively. And 34 strain-specific spots, corresponding to 27 proteins, were identified successfully by MALDI-TOF mass spectrometry. Among them, 23 proteins presented exclusively in S. agalactiae TFJ0901 or THN0901, and the other 4 proteins presented in different isomeric forms between TFJ0901 and THN0901. Most of the strain-specific proteins were just involved in metabolic pathways, while 7 of them were presumed to be responsible for the virulence differences of S. agalactiae strain TFJ0901 and THN0901, including molecular chaperone DnaJ, dihydrolipoamide dehydrogenase, thioredoxin, manganese-dependent inorganic pyrophosphatase, elongation factor Tu, bleomycin resistance protein and cell division protein DivIVA. These virulence-associated proteins may contribute to identify new

  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. 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

  20. Identification of immunoreactive extracellular proteins of Streptococcus agalactiae in bovine mastitis.

    PubMed

    Trigo, Gabriela; Ferreira, Paula; Ribeiro, Niza; Dinis, Márcia; Andrade, Elva Bonifácio; Melo-Cristino, José; Ramirez, Mário; Tavares, Delfina

    2008-11-01

    Streptococcus agalactiae is a common pathogen that causes bovine mastitis. The aims of this study were to evaluate the antibody response against S. agalactiae extracellular proteins in the whey and serum of naturally infected bovines and to identify possible immunodominant extracellular antigens. IgG1 antibodies against S. agalactiae extracellular proteins were elevated in the whey and serum of naturally infected bovines. In the whey, the levels of IgG1 specific for S. agalactiae extracellular proteins were similar in infected and noninfected milk quarters from the same cow, and the production of antibodies specific for S. agalactiae extracellular proteins was induced only by infection with this bacterium. The immunoreactivity of extracellular proteins with bovine whey was clearly different in infected versus control animals. Group B protective surface protein and 5'-nucleotidase family protein were 2 major immunoreactive proteins that were detected only in the whey of infected cows, suggesting that these proteins may be important in the pathogenesis of S. agalactiae-induced mastitis. This information could be used to diagnose S. agalactiae infection. In addition, these antigens may be useful as carrier proteins for serotype-specific polysaccharides in conjugate vaccines.

  1. [Culture media for the detection and the identification of Streptococcus agalactiae].

    PubMed

    de la Rosa, M; Pérez, M; Carazo, C; Pareja, L; Orts, A; Cantudo, P

    1994-01-01

    Streptococcus agalactiae, a Group B streptococcus, is the main cause of bacterial perinatal infection and is also an important opportunistic pathogen. Detection and identification of S. agalactiae are straight forward with special culture media, where Group B streptococci show a specific, typical pink or red pigment. To quickly and easily detect the pigment, culture media should contain: (i) starch; (ii) an inhibitor of the folate pathway; (iii) animal serum; (iv) a pepsic proteic hydrolysate; and (v) glucose, together with a high-capacity buffer. When selective antibiotics are added to culture media designed in this way, it is possible to detect S. agalactiae directly from clinical samples by observation of its pigment after less than 12 hours of aerobic incubation.

  2. 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

  3. Complete genome sequence of an attenuated Sparfloxacin-resistant Streptococcus agalactiae strain 138spar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complete genome of a sparfloxacin-resistant Streptococcus agalactiae vaccine strain 138spar is 1,838,126 bp in size. The genome has 1892 coding sequences and 82 RNAs. The annotation of the genome is added by the NCBI Prokaryotic Genome Annotation Pipeline. The publishing of this genome will allo...

  4. 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

  5. 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

  6. Genome Sequence of Streptococcus agalactiae Strain 09mas018883, Isolated from a Swedish Cow.

    PubMed

    Zubair, S; de Villiers, E P; Fuxelius, H H; Andersson, G; Johansson, K-E; Bishop, R P; Bongcam-Rudloff, E

    2013-01-01

    We announce the complete genome sequence of Streptococcus agalactiae strain 09mas018883, isolated from the milk of a cow with clinical mastitis. The availability of this genome may allow identification of candidate genes, leading to discovery of antigens that might form the basis for development of a vaccine as an alternative means of mastitis control. PMID:23846269

  7. Novel substrate specificity of glutathione synthesis enzymes from Streptococcus agalactiae and Clostridium acetobutylicum

    SciTech Connect

    Kino, Kuniki . E-mail: kkino@waseda.jp; Kuratsu, Shoko; Noguchi, Atsushi; Kokubo, Masahiro; Nakazawa, Yuji; Arai, Toshinobu; Yagasaki, Makoto; Kirimura, Kohtaro

    2007-01-12

    Glutathione (GSH) is synthesized by {gamma}-glutamylcysteine synthetase ({gamma}-GCS) and glutathione synthetase (GS) in living organisms. Recently, bifunctional fusion protein, termed {gamma}-GCS-GS catalyzing both {gamma}-GCS and GS reactions from gram-positive firmicutes Streptococcus agalactiae, has been reported. We revealed that in the {gamma}-GCS activity, S. agalactiae {gamma}-GCS-GS had different substrate specificities from those of Escherichia coli {gamma}-GCS. Furthermore, S. agalactiae {gamma}-GCS-GS synthesized several kinds of {gamma}-glutamyltripeptide, {gamma}-Glu-X{sub aa}-Gly, from free three amino acids. In Clostridium acetobutylicum, the genes encoding {gamma}-GCS and putative GS were found to be immediately adjacent by BLAST search, and had amino acid sequence homology with S. agalactiae {gamma}-GCS-GS, respectively. We confirmed that the proteins expressed from each gene showed {gamma}-GCS and GS activity, respectively. C. acetobutylicum GS had broad substrate specificities and synthesized several kinds of {gamma}-glutamyltripeptide, {gamma}-Glu-Cys-X{sub aa}. Whereas the substrate specificities of {gamma}-GCS domain protein and GS domain protein of S. agalactiae {gamma}-GCS-GS were the same as those of S. agalactiae {gamma}-GCS-GS.

  8. Annual incidence, prevalence and transmission characteristics of Streptococcus agalactiae in Danish dairy herds.

    PubMed

    Mweu, Marshal M; Nielsen, Søren S; Halasa, Tariq; Toft, Nils

    2012-10-01

    Contagious mastitis pathogens continue to pose an economic threat to the dairy industry. An understanding of their frequency and transmission dynamics is central to evaluating the effectiveness of control programmes. The objectives of this study were twofold: (1) to estimate the annual herd-level incidence rates and apparent prevalences of Streptococcus agalactiae (S. agalactiae) in the population of Danish dairy cattle herds over a 10-year period from 2000 to 2009 inclusive and (2) to estimate the herd-level entry and exit rates (demographic parameters), the transmission parameter, β, and recovery rate for S. agalactiae infection. Data covering the specified period, on bacteriological culture of all bulk tank milk samples collected annually as part of the mandatory Danish S. agalactiae surveillance scheme, were extracted from the Danish Cattle Database and subsequently analysed. There was an increasing trend in both the incidence and prevalence of S. agalactiae over the study period. Per 100 herd-years the value of β was 54.1 (95% confidence interval [CI] 46.0-63.7); entry rate 0.3 (95% CI 0.2-0.4); infection-related exit rate 7.1 (95% CI 5.6-8.9); non-infection related exit rate 9.2 (95% CI 7.4-11.5) and recovery rate 40.0 (95% CI 36.8-43.5). This study demonstrates a need to tighten the current controls against S. agalactiae in order to lower its incidence. PMID:22560559

  9. Inapparent Streptococcus agalactiae infection in adult/commercial tilapia.

    PubMed

    Sun, Jiufeng; Fang, Wei; Ke, Bixia; He, Dongmei; Liang, Yuheng; Ning, Dan; Tan, Hailing; Peng, Hualin; Wang, Yunxin; Ma, Yazhou; Ke, Changwen; Deng, Xiaoling

    2016-01-01

    We report on inapparent infections in adult/commercial tilapia in major tilapia fish farms in Guangdong. A total of 146 suspected isolates were confirmed to be S. agalactiae using an API 20 Strep system and specific PCR amplification. All isolates were identified as serotype Ia using multiplex serotyping PCR. An MLST assay showed single alleles of adhP (10), atr (2), glcK (2), glnA (1), pheS (1), sdhA (3) and tkt (2), and this profile was designated 'unique ST 7'. The analysis of virulence genes resulted in 10 clusters, of which dltr-bca-sodA-spb1-cfb-bac (62, 42.47%) was the predominant virulence gene profile. The PFGE analysis of S. agalactiae yielded 6 distinct PFGE types (A, B, C, D, F and G), of which Pattern C (103) was the predominant type, accounting for approximately 70.55% (103/146) of the total S. agalactiae strains. Therefore, unlike what has been found in juvenile tilapia, in which PFGE pattern D/F is the major prevalent pattern, we found that pattern C was the major prevalent pattern in inapparent infected adult/commercial tilapia in Guangdong, China. In conclusion, we close a gap in the current understanding of S. agalactiae epidemiology and propose that researchers should be alert for inapparent S. agalactiae infections in adult/commercial tilapia to prevent a potential threat to food safety. PMID:27215811

  10. Inapparent Streptococcus agalactiae infection in adult/commercial tilapia

    PubMed Central

    Sun, Jiufeng; Fang, Wei; Ke, Bixia; He, Dongmei; Liang, Yuheng; Ning, Dan; Tan, Hailing; Peng, Hualin; Wang, Yunxin; Ma, Yazhou; Ke, Changwen; Deng, Xiaoling

    2016-01-01

    We report on inapparent infections in adult/commercial tilapia in major tilapia fish farms in Guangdong. A total of 146 suspected isolates were confirmed to be S. agalactiae using an API 20 Strep system and specific PCR amplification. All isolates were identified as serotype Ia using multiplex serotyping PCR. An MLST assay showed single alleles of adhP (10), atr (2), glcK (2), glnA (1), pheS (1), sdhA (3) and tkt (2), and this profile was designated ‘unique ST 7’. The analysis of virulence genes resulted in 10 clusters, of which dltr-bca-sodA-spb1-cfb-bac (62, 42.47%) was the predominant virulence gene profile. The PFGE analysis of S. agalactiae yielded 6 distinct PFGE types (A, B, C, D, F and G), of which Pattern C (103) was the predominant type, accounting for approximately 70.55% (103/146) of the total S. agalactiae strains. Therefore, unlike what has been found in juvenile tilapia, in which PFGE pattern D/F is the major prevalent pattern, we found that pattern C was the major prevalent pattern in inapparent infected adult/commercial tilapia in Guangdong, China. In conclusion, we close a gap in the current understanding of S. agalactiae epidemiology and propose that researchers should be alert for inapparent S. agalactiae infections in adult/commercial tilapia to prevent a potential threat to food safety. PMID:27215811

  11. Fluoroquinolone-resistant Streptococcus agalactiae isolates from Argentina.

    PubMed

    Faccone, D; Guerriero, L; Méndez, E; Errecalde, L; Cano, H; Yoyas, N; Togneri, A; Romanowski, V; Galas, M; Whonet, Red; Corso, A

    2010-01-01

    Fluoroquinolone resistance is a growing problem that has only recently emerged in S. agalactiae. Between 2005-2007, WHONET--Argentina network evaluated levofloxacin susceptibility in 1128 clinical S. agalactiae isolates, 10 (0.9%) of which proved to be resistant. Nine of them had come from 5 hospitals (in Buenos Aires City and 4 Argentinean provinces) and recovered from urine (n=7) and vaginal screening cultures (n=2). Three strains were also resistant to macrolides, lincosamides and B streptogramins due to the ermA gene. All nine fluoroquinolone-resistant isolates bore the same two mutations, Ser79Phe in ParC and Ser81Leu in GyrA proteins. Genetic relationships were analyzed by Apal-PFGE and two clones were determined, A (n=6) and B (n=3). To our knowledge, these are the first fluoroquinolone-resistant S. agalactiae isolates detected in Latin America.

  12. Biofilm formation by Streptococcus agalactiae: influence of environmental conditions and implicated virulence factors

    PubMed Central

    Rosini, Roberto; Margarit, Immaculada

    2015-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is an important human pathogen that colonizes the urogenital and/or the lower gastro-intestinal tract of up to 40% of healthy women of reproductive age and is a leading cause of sepsis and meningitis in the neonates. GBS can also infect the elderly and immuno-compromised adults, and is responsible for mastitis in bovines. Like other Gram-positive bacteria, GBS can form biofilm-like three-dimensional structures that could enhance its ability to colonize and persist in the host. Biofilm formation by GBS has been investigated in vitro and appears tightly controlled by environmental conditions. Several adhesins have been shown to play a role in the formation of GBS biofilm-like structures, among which are the protein components of pili protruding outside the bacterial surface. Remarkably, antibodies directed against pilus proteins can prevent the formation of biofilms. The implications of biofilm formation in the context of GBS asymptomatic colonization and dissemination to cause invasive disease remain to be investigated in detail. PMID:25699242

  13. Remodeling of the Streptococcus agalactiae Transcriptome in Response to Growth Temperature

    PubMed Central

    Mereghetti, Laurent; Sitkiewicz, Izabela; Green, Nicole M.; Musser, James M.

    2008-01-01

    Background To act as a commensal bacterium and a pathogen in humans and animals, Streptococcus agalactiae (group B streptococcus, GBS) must be able to monitor and adapt to different environmental conditions. Temperature variation is a one of the most commonly encountered variables. Methodology/Principal Findings To understand the extent to which GBS modify gene expression in response to temperatures encountered in the various hosts, we conducted a whole genome transcriptome analysis of organisms grown at 30°C and 40°C. We identified extensive transcriptome remodeling at various stages of growth, especially in the stationary phase (significant transcript changes occurred for 25% of the genes). A large proportion of genes involved in metabolism was up-regulated at 30°C in stationary phase. Conversely, genes up-regulated at 40°C relative to 30°C include those encoding virulence factors such as hemolysins and extracellular secreted proteins with LPXTG motifs. Over-expression of hemolysins was linked to larger zones of hemolysis and enhanced hemolytic activity at 40°C. A key theme identified by our study was that genes involved in purine metabolism and iron acquisition were significantly up-regulated at 40°C. Conclusion/Significance Growth of GBS in vitro at different temperatures resulted in extensive remodeling of the transcriptome, including genes encoding proven and putative virulence genes. The data provide extensive new leads for molecular pathogenesis research. PMID:18665215

  14. Evaluation of two iodophor teat germicides: activity against Staphylococcus aureus and Streptococcus agalactiae.

    PubMed

    Boddie, R L; Nickerson, S C

    1997-08-01

    Two germicides containing 0.5 and 1% titratable iodine were tested for efficacy against the development of new intramammary infections (IMI) caused by Staphylococcus aureus and Streptococcus agalactiae. The two trials for postmilking teat dip used a model for experimental challenge that was recommended by the National Mastitis Council. The 0.5% iodine formulation reduced new Staph. aureus IMI by 78.2% and reduced new Strep. agalactiae IMI by 73.2%. The 1% iodine product reduced new Staph. aureus IMI by 43.5% and reduced new Strep. agalactiae IMI by 46.4%. No adverse effects on the condition of teat skin or on teat ends were observed over the course of the trials. At the completion of each trial, the teat skin of dipped quarters was characterized as normal, smooth skin that was free from scales, cracks, or chapping; the teat orifice was characterized as smooth without evidence of irritation. PMID:9276825

  15. Experimental early pathogenesis of Streptococcus agalactiae infection in red tilapia Oreochromis spp.

    PubMed

    Iregui, C A; Comas, J; Vásquez, G M; Verján, N

    2016-02-01

    Streptococcus agalactiae causes a severe systemic disease in fish, and the routes of entry are still ill-defined. To address this issue, two groups of 33 red tilapia Oreochromis spp. each of 10 g were orally infected with S. agalactiae (n = 30), and by immersion (n = 30), six individuals were control-uninfected fish. Three tilapias were killed at each time point from 30 min to 96 h post-inoculation (pi); controls were killed at 96 h. Samples from most tissues were examined by haematoxylin-eosin (H&E), indirect immunoperoxidase (IPI) and periodic acid-Schiff; only intestine from fish infected by gavage was evaluated by transmission electron microscopy. The results of both experiments suggest that the main entry site of S. agalactiae in tilapia is the gastrointestinal epithelium; mucus seems to play an important defensive role, and environmental conditions may be an important predisposing factor for the infection. PMID:25683349

  16. Development of an indirect ELISA for bovine mastitis using Sip protein of Streptococcus agalactiae

    PubMed Central

    Bu, R. E; Wang, J. L; DebRoy, C; Wu, J. H; Xi, L. G. W; Liu, Y; Shen, Z. Q

    2015-01-01

    The sip gene encoding for a conserved highly immunogenic surface protein of Streptococcus agalactiae was amplified using polymerase chain reaction (PCR) and subcloned into prokaryotic expression vector pET32a (+) and expressed as a recombinant protein in E. coli BL21 (DE3). An indirect enzyme linked immunosorbent assay (ELISA) was developed using the purified Sip protein as a coating antigen, which could identify S. agalactiae specific antibody in sera. The coating antigen at a concentration of 3.125 μg/ml, serum diluted to 1:160, and HRP-conjugated secondary antibody concentration at 1:4000 was found to be most effective in exhibiting positive result. The ELISA was found to be highly specific for S. agalactiae that may be used for the detection of the pathogen in mastitis cases, for epidemiological studies and for surveillance. PMID:27175190

  17. 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

    2015-05-26

    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.

  18. 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

  19. 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

  20. Streptococcus agalactiae in the environment of bovine dairy herds--rewriting the textbooks?

    PubMed

    Jørgensen, H J; Nordstoga, A B; Sviland, S; Zadoks, R N; Sølverød, L; Kvitle, B; Mørk, T

    2016-02-29

    Many free-stall bovine dairy herds in Norway fail to eradicate Streptococcus agalactiae despite long-term control measures. In a longitudinal study of 4 free-stall herds with automatic milking systems (AMS), milk and extramammary sites were sampled 4 times with 1-2 month intervals. Composite milk, rectal- and vaginal swabs were collected from dairy cows; rectal swabs from heifers and young stock; rectal- and tonsillar swabs from calves; and environmental swabs from the AMS, the floors, cow beds, watering and feeding equipment. A cross sectional study of 37 herds was also conducted, with 1 visit for environmental sampling. Fifteen of the herds were known to be infected with S. agalactiae while the remaining 22 had not had evidence of S. agalactiae mastitis in the preceding 2 years. All samples were cultured for S. agalactiae, and selected isolates (n=54) from positive herds were genotyped by Multi Locus Sequence Typing (MLST). Results show that the bovine gastrointestinal tract and the dairy cow environment are reservoirs of S. agalactiae, and point to the existence of 2 transmission cycles; a contagious transmission cycle via the milking machine and an oro-fecal transmission cycle, with drinking water as the most likely vehicle for transmission. Ten sequence types were identified, and results suggest that strains differ in their ability to survive in the environment and transmit within dairy herds. Measures to eradicate S. agalactiae from bovine dairy herds should take into account the extra-mammary reservoirs and the potential for environmental transmission of this supposedly exclusively contagious pathogen.

  1. Streptococcus agalactiae in the environment of bovine dairy herds--rewriting the textbooks?

    PubMed

    Jørgensen, H J; Nordstoga, A B; Sviland, S; Zadoks, R N; Sølverød, L; Kvitle, B; Mørk, T

    2016-02-29

    Many free-stall bovine dairy herds in Norway fail to eradicate Streptococcus agalactiae despite long-term control measures. In a longitudinal study of 4 free-stall herds with automatic milking systems (AMS), milk and extramammary sites were sampled 4 times with 1-2 month intervals. Composite milk, rectal- and vaginal swabs were collected from dairy cows; rectal swabs from heifers and young stock; rectal- and tonsillar swabs from calves; and environmental swabs from the AMS, the floors, cow beds, watering and feeding equipment. A cross sectional study of 37 herds was also conducted, with 1 visit for environmental sampling. Fifteen of the herds were known to be infected with S. agalactiae while the remaining 22 had not had evidence of S. agalactiae mastitis in the preceding 2 years. All samples were cultured for S. agalactiae, and selected isolates (n=54) from positive herds were genotyped by Multi Locus Sequence Typing (MLST). Results show that the bovine gastrointestinal tract and the dairy cow environment are reservoirs of S. agalactiae, and point to the existence of 2 transmission cycles; a contagious transmission cycle via the milking machine and an oro-fecal transmission cycle, with drinking water as the most likely vehicle for transmission. Ten sequence types were identified, and results suggest that strains differ in their ability to survive in the environment and transmit within dairy herds. Measures to eradicate S. agalactiae from bovine dairy herds should take into account the extra-mammary reservoirs and the potential for environmental transmission of this supposedly exclusively contagious pathogen. PMID:26854346

  2. Leukocyte populations and cytokine expression in the mammary gland in a mouse model of Streptococcus agalactiae mastitis.

    PubMed

    Trigo, Gabriela; Dinis, Márcia; França, Angela; Bonifácio Andrade, Elva; Gil da Costa, Rui M; Ferreira, Paula; Tavares, Delfina

    2009-07-01

    Streptococcus agalactiae is a contagious, mastitis-causing pathogen that is highly adapted to survive in the bovine mammary gland. This study used a BALB/c mouse model of Streptococcus agalactiae mastitis to evaluate leukocyte populations in regional lymph nodes and cytokine expression in the mammary gland involved in the immune response against Streptococcus agalactiae. It was found that the bacteria replicated efficiently in the mammary gland, peaking after 24 h and increasing by 100-fold. Dissemination of bacteria to systemic organs was observed 6 h after infection. At the same time, a massive infiltration of polymorphonuclear cells and an increase in the inflammatory cytokines interleukin (IL)-1beta, IL-6 and tumour necrosis factor-alpha were detected in mammary glands, indicating an early inflammatory response. A decrease in the levels of inflammatory cytokines in mammary glands was observed 72 h after infection, accompanied by an increase in the levels of IL-12 and IL-10, which were related to a gradual decrease in bacterial load. An increase in the number of macrophages and B220(+) lymphocytes and similar increases in both CD4(+) and CD8(+) T cells in regional lymph nodes were observed, being most pronounced 5 days after infection. Moreover, increased levels of anti-Streptococcus agalactiae antibodies in the mammary gland were observed 10 days after infection. Overall, these data suggest that the host exhibits both innate and acquired immune responses in response to Streptococcus agalactiae mastitis.

  3. Reductive evolution in Streptococcus agalactiae and the emergence of a host adapted lineage

    PubMed Central

    2013-01-01

    Background During host specialization, inactivation of genes whose function is no more required is favored by changes in selective constraints and evolutionary bottlenecks. The Gram positive bacteria Streptococcus agalactiae (also called GBS), responsible for septicemia and meningitis in neonates also emerged during the seventies as a cause of severe epidemics in fish farms. To decipher the genetic basis for the emergence of these highly virulent GBS strains and of their adaptation to fish, we have analyzed the genomic sequence of seven strains isolated from fish and other poikilotherms. Results Comparative analysis shows that the two groups of GBS strains responsible for fish epidemic diseases are only distantly related. While strains belonging to the clonal complex 7 cannot be distinguished from their human CC7 counterparts according to their gene content, strains belonging to the ST260-261 types probably diverged a long time ago. In this lineage, specialization to the fish host was correlated with a massive gene inactivation and broad changes in gene expression. We took advantage of the low level of sequence divergence between GBS strains and of the emergence of sublineages to reconstruct the different steps involved in this process. Non-homologous recombination was found to have played a major role in the genome erosion. Conclusions Our results show that the early phase of genome reduction during host specialization mostly involves accumulation of small and likely reversible indels, followed by a second evolutionary step marked by a higher frequency of large deletions. PMID:23586779

  4. Streptococcus agalactiae capsule polymer length and attachment is determined by the proteins CpsABCD.

    PubMed

    Toniolo, Chiara; Balducci, Evita; Romano, Maria Rosaria; Proietti, Daniela; Ferlenghi, Ilaria; Grandi, Guido; Berti, Francesco; Ros, Immaculada Margarit Y; Janulczyk, Robert

    2015-04-10

    The production of capsular polysaccharides (CPS) or secreted exopolysaccharides is ubiquitous in bacteria, and the Wzy pathway constitutes a prototypical mechanism to produce these structures. Despite the differences in polysaccharide composition among species, a group of proteins involved in this pathway is well conserved. Streptococcus agalactiae (group B Streptococcus; GBS) produces a CPS that represents the main virulence factor of the bacterium and is a prime target in current vaccine development. We used this human pathogen to investigate the roles and potential interdependencies of the conserved proteins CpsABCD encoded in the cps operon, by developing knock-out and functional mutant strains. The mutant strains were examined for CPS quantity, size, and attachment to the cell surface as well as CpsD phosphorylation. We observed that CpsB, -C, and -D compose a phosphoregulatory system where the CpsD autokinase phosphorylates its C-terminal tyrosines in a CpsC-dependent manner. These Tyr residues are also the target of the cognate CpsB phosphatase. An interaction between CpsD and CpsC was observed, and the phosphorylation state of CpsD influenced the subsequent action of CpsC. The CpsC extracellular domain appeared necessary for the production of high molecular weight polysaccharides by influencing CpsA-mediated attachment of the CPS to the bacterial cell surface. In conclusion, although having no impact on cps transcription or the synthesis of the basal repeating unit, we suggest that these proteins are fine-tuning the last steps of CPS biosynthesis (i.e. the balance between polymerization and attachment to the cell wall).

  5. Molecular characterization of Streptococcus agalactiae isolated from bovine mastitis in Eastern China.

    PubMed

    Yang, Yongchun; Liu, Yinglong; Ding, Yunlei; Yi, Li; Ma, Zhe; Fan, Hongjie; Lu, Chengping

    2013-01-01

    One hundred and two Streptococcus agalactiae (group B streptococcus [GBS]) isolates were collected from dairy cattle with subclinical mastitis in Eastern China during 2011. Clonal groups were established by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE), respectively. Capsular polysaccharides (CPS), pilus and alpha-like-protein (Alp) family genes were also characterized by molecular techniques. MLST analysis revealed that these isolates were limited to three clonal groups and were clustered in six different lineages, i.e. ST (sequence type) 103, ST568, ST67, ST301, ST313 and ST570, of which ST568 and ST570 were new genotypes. PFGE analysis revealed this isolates were clustered in 27 PFGE types, of which, types 7, 8, 14, 15, 16, 18, 23 and 25 were the eight major types, comprising close to 70% (71/102) of all the isolates. The most prevalent sequence types were ST103 (58% isolates) and ST568 (31% isolates), comprising capsular genotype Ia isolates without any of the detected Alp genes, suggesting the appearance of novel genomic backgrounds of prevalent strains of bovine S. agalactiae. All the strains possessed the pilus island 2b (PI-2b) gene and the prevalent capsular genotypes were types Ia (89% isolates) and II (11% isolates), the conserved pilus type providing suitable data for the development of vaccines against mastitis caused by S. agalactiae. PMID:23874442

  6. Efficacy of teat dips containing a hypochlorous acid germicide against experimental challenge with Staphylococcus aureus and Streptococcus agalactiae.

    PubMed

    Boddie, R L; Nickerson, S C

    1996-09-01

    Two teat dip formulations containing sodium dichloroisocyanurate, which released hypochlorous acid (2800 ppm) as the active ingredient, were tested for efficacy against new Staphylococcus aureus and Streptococcus agalactiae IMI using an experimental challenge model. Product 1 reduced the number of new Staph. aureus IMI by 73.6% and reduced the number of new Strep. agalactiae IMI by 65.1%. Product 2 reduced the number of new Staph. aureus IMI by 69.0% and reduced the number of new Strep. agalactiae IMI by 63.5%. No adverse effects on teat skin condition were observed over the course of the studies. PMID:8899537

  7. Molecular detection of Streptococcus agalactiae in bovine raw milk samples obtained directly from bulk tanks.

    PubMed

    Elias, Acácia Orieth; Cortez, Adriana; Brandão, Paulo Eduardo; da Silva, Rodrigo Costa; Langoni, Helio

    2012-08-01

    Mastitis is the most common infectious disease affecting dairy cattle; in addition, it remains the most economically important disease of dairy industries around the world. Streptococcus agalactiae, a contagious pathogen associated with subclinical mastitis, is highly infectious. This bacterium can cause an increase in bulk tank bacterial counts (BTBC) and bulk tank somatic cell counts (BTSCC). The microbiological identification of S. agalactiae in samples from bulk tanks is an auxiliary method to control contagious mastitis. Thus, there are some limitations for time-consuming cultures or identification methods and additional concerns about the conservation and transport of samples. Bulk tank samples from 247 dairy farms were cultured and compared through polymerase chain reaction (PCR), directed to 16S rRNA genes of S. agalactiae, followed by BTBC and S. agalactiae isolation. The mean value of BTBC was 1.08×10(6) CFU mL(-1) and the bacterium was identified through the microbiological method in 98 (39.7%; CI(95%)=33.8-45.9%) and through PCR in 110 (44.5%; CI(95%)=38.5-50.8%) samples. Results indicated sensitivity of 0.8571±0.0353 (CI(95%)=0.7719-0.9196) and specificity of 0.8255±0.0311 (CI(95%)=0.7549-0.8827). The lack of significant difference between microbiological and molecular results (κ=0.6686±0.0477 and CI(95%)=0.5752-0.7620) indicated substantial agreement between the methods. This suggests that PCR can be used for bulk tank samples to detect contagious mastitis caused by S. agalactiae.

  8. Significance, management and prevention of Streptococcus agalactiae infection during the perinatal period.

    PubMed

    Berner, Reinhard

    2004-06-01

    The highest annual death rate during the first five decades of life occurs in the first year, particularly during the perinatal period between the onset of labor and 72 h after birth. Invasive bacterial disease evoking the severe inflammatory response syndrome is a leading cause of perinatal morbidity and mortality. Group B streptococcus (Streptococcus agalactiae) is the most important pathogen in this period of life, although the concept of intrapartum antimicrobial prophylaxis has impressively reduced the rate of culture-proven invasive infection in neonates. This strategy, however, has considerable limitations since group B streptococcus-related stillbirths or prematurity and late-onset sepsis cannot be prevented. Moreover, the use of intrapartum antimicrobial prophylaxis has significantly increased the use of antibiotics during labor and therefore may select for intrapartum infections caused by other bacteria, including those resistant to antibiotics. Several advances in the development of vaccines and research on virulence factors and pathways involved in the immune response to group B streptococcus have been accomplished within the last years, including complete sequencing of the group B streptococcus genome. Development of effective vaccines and implementation of vaccination strategies will be one of the key challenges in the future for prevention of neonatal group B Streptococcus infections.

  9. Streptococcus agalactiae septicemia in a patient with diabetes and hepatic cirrhosis

    PubMed Central

    Ferreira, Cristiane Rúbia

    2015-01-01

    Streptococcus agalactiae is a well-known pathogen during pregnancy and in neonates. Among non-pregnant adults, invasive infection, although rare, is showing increasing frequency, especially in chronically ill, immunosuppressed, or older patients. Although rare, the clinical features of meningeal infection caused by S. agalactiae are similar to other bacterial meningitis. The authors report the case of a middle-aged man previously diagnosed with hypertension, diabetes mellitus, and alcoholic liver cirrhosis, who was admitted at the emergency department with a Glasgow Coma Scale of 11/12, generalized spasticity, bilateral Babinski sign, and hypertension. The clinical outcome was bad, with refractory shock and death within 24 hours of hospitalization. The bacteriological work-up isolated S. agalactiae in the cerebral spinal fluid (CSF), blood, and urine. An autopsy revealed meningoencephalitis, acute myocardial infarction, and pyelonephritis due to septic emboli. The authors point out the atypical CSF findings, the rapid fatal outcome, and the importance of including this pathogen among the etiologic possibilities of invasive infections in this group of patients. PMID:26894044

  10. Efficacy of two barrier teat dips containing chlorous acid germicides against experimental challenge with Staphylococcus aureus and Streptococcus agalactiae.

    PubMed

    Boddie, R L; Nickerson, S C; Kemp, G K

    1994-10-01

    Two postmilking teat dips were tested for efficacy against Staphylococcus aureus and Streptococcus agalactiae using experimental challenge procedures recommended by the National Mastitis Council. Both dips contained chlorous acid as the primary germicidal agent and lactic acid or mandelic acid as the chlorous acid activator. The dip activated with mandelic acid significantly reduced new IMI by Staph. aureus and Strep. agalactiae. The IMI rate was reduced 68.7% for Staph. aureus and 56.4% for Strep. agalactiae. The dip activated with lactic acid significantly reduced new Staph. aureus IMI by 69.3% but did not significantly reduce new Strep. agalactiae IMI (35.2% reduction) through the full 11-wk study period. Teat skin condition did not change from pretrial status after using either teat dip during the study. PMID:7836608

  11. Overexpression, purification, crystallization and preliminary X-ray diffraction of the nisin resistance protein from Streptococcus agalactiae.

    PubMed

    Khosa, Sakshi; Hoeppner, Astrid; Kleinschrodt, Diana; Smits, Sander H J

    2015-06-01

    Nisin is a 34-amino-acid antimicrobial peptide produced by Lactococcus lactis belonging to the class of lantibiotics. Nisin displays a high bactericidal activity against various Gram-positive bacteria, including some human-pathogenic strains. However, there are some nisin-non-producing strains that are naturally resistant owing to the presence of the nsr gene within their genome. The encoded protein, NSR, cleaves off the last six amino acids of nisin, thereby reducing its bactericidal efficacy. An expression and purification protocol has been established for the NSR protein from Streptococcus agalactiae COH1. The protein was successfully crystallized using the vapour-diffusion method in hanging and sitting drops, resulting in crystals that diffracted X-rays to 2.8 and 2.2 Å, respectively. PMID:26057793

  12. Structure of the Response Regulator NsrR from Streptococcus agalactiae, Which Is Involved in Lantibiotic Resistance.

    PubMed

    Khosa, Sakshi; Hoeppner, Astrid; Gohlke, Holger; Schmitt, Lutz; Smits, Sander H J

    2016-01-01

    Lantibiotics are antimicrobial peptides produced by Gram-positive bacteria. Interestingly, several clinically relevant and human pathogenic strains are inherently resistant towards lantibiotics. The expression of the genes responsible for lantibiotic resistance is regulated by a specific two-component system consisting of a histidine kinase and a response regulator. Here, we focused on a response regulator involved in lantibiotic resistance, NsrR from Streptococcus agalactiae, and determined the crystal structures of its N-terminal receiver domain and C-terminal DNA-binding effector domain. The C-terminal domain exhibits a fold that classifies NsrR as a member of the OmpR/PhoB subfamily of regulators. Amino acids involved in phosphorylation, dimerization, and DNA-binding were identified and demonstrated to be conserved in lantibiotic resistance regulators. Finally, a model of the full-length NsrR in the active and inactive state provides insights into protein dimerization and DNA-binding. PMID:26930060

  13. Overexpression, purification, crystallization and preliminary X-ray diffraction of the nisin resistance protein from Streptococcus agalactiae.

    PubMed

    Khosa, Sakshi; Hoeppner, Astrid; Kleinschrodt, Diana; Smits, Sander H J

    2015-06-01

    Nisin is a 34-amino-acid antimicrobial peptide produced by Lactococcus lactis belonging to the class of lantibiotics. Nisin displays a high bactericidal activity against various Gram-positive bacteria, including some human-pathogenic strains. However, there are some nisin-non-producing strains that are naturally resistant owing to the presence of the nsr gene within their genome. The encoded protein, NSR, cleaves off the last six amino acids of nisin, thereby reducing its bactericidal efficacy. An expression and purification protocol has been established for the NSR protein from Streptococcus agalactiae COH1. The protein was successfully crystallized using the vapour-diffusion method in hanging and sitting drops, resulting in crystals that diffracted X-rays to 2.8 and 2.2 Å, respectively.

  14. Structure of the Response Regulator NsrR from Streptococcus agalactiae, Which Is Involved in Lantibiotic Resistance

    PubMed Central

    Khosa, Sakshi; Hoeppner, Astrid; Gohlke, Holger; Schmitt, Lutz; Smits, Sander H. J.

    2016-01-01

    Lantibiotics are antimicrobial peptides produced by Gram-positive bacteria. Interestingly, several clinically relevant and human pathogenic strains are inherently resistant towards lantibiotics. The expression of the genes responsible for lantibiotic resistance is regulated by a specific two-component system consisting of a histidine kinase and a response regulator. Here, we focused on a response regulator involved in lantibiotic resistance, NsrR from Streptococcus agalactiae, and determined the crystal structures of its N-terminal receiver domain and C-terminal DNA-binding effector domain. The C-terminal domain exhibits a fold that classifies NsrR as a member of the OmpR/PhoB subfamily of regulators. Amino acids involved in phosphorylation, dimerization, and DNA-binding were identified and demonstrated to be conserved in lantibiotic resistance regulators. Finally, a model of the full-length NsrR in the active and inactive state provides insights into protein dimerization and DNA-binding. PMID:26930060

  15. Interaction of Streptococcus agalactiae and Cellular Innate Immunity in Colonization and Disease

    PubMed Central

    Landwehr-Kenzel, Sybille; Henneke, Philipp

    2014-01-01

    Streptococcus agalactiae (Group B streptococcus, GBS) is highly adapted to humans, where it is a normal constituent of the intestinal and vaginal flora. Yet, GBS has highly invasive potential and causes excessive inflammation, sepsis, and death at the beginning of life, in the elderly and in diabetic patients. Thus, GBS is a model pathobiont that thrives in the healthy host, but has not lost its potential virulence during coevolution with mankind. It remains incompletely understood how the innate immune system contains GBS in the natural niches, the intestinal and genital tracts, and which molecular events underlie breakdown of mucocutaneous resistance. Newborn infants between days 7 and 90 of life are at risk of a particularly striking sepsis manifestation (late-onset disease), where the transition from colonization to invasion and dissemination, and thus from health to severe sepsis is typically fulminant and not predictable. The great majority of late-onset sepsis cases are caused by one clone, GBS ST17, which expresses HvgA as a signature virulence factor and adhesin. In mice, HvgA promotes the crossing of both the mucosal and the blood–brain barrier. Expression levels of HvgA and other GBS virulence factors, such as pili and toxins, are regulated by the upstream two-component control system CovR/S. This in turn is modulated by acidic epithelial pH, high glucose levels, and during the passage through the mouse intestine. After invasion, GBS has the ability to subvert innate immunity by mechanisms like glycerinaldehyde-3-phosphate-dehydrogenase-dependent induction of IL-10 and β-protein binding to the inhibitory phagocyte receptors sialic acid binding immunoglobulin-like lectin 5 and 14. On the host side, sensing of GBS nucleic acids and lipopeptides by both Toll-like receptors and the inflammasome appears to be critical for host resistance against GBS. Yet, comprehensive models on the interplay between GBS and human immune cells at the colonizing site are

  16. Development of live attenuated Streptococcus agalactiae vaccine for tilapia via continuous passage in vitro.

    PubMed

    Li, L P; Wang, R; Liang, W W; Huang, T; Huang, Y; Luo, F G; Lei, A Y; Chen, M; Gan, X

    2015-08-01

    Fish Streptococcus agalactiae (S. agalactiae) seriously harms the world's aquaculture industry and causes huge economic losses. This study aimed to develop a potential live attenuated vaccine of S. agalactiae. Pre-screened vaccine candidate strain S. agalactiae HN016 was used as starting material to generate an attenuated strain S. agalactiae YM001 by continuous passage in vitro. The biological characteristics, virulence, and stability of YM001 were detected, and the protective efficacy of YM001 immunization in tilapia was also determined. Our results indicated that the growth, staining, characteristics of pulsed-field gel electrophoresis (PFGE) genotype, and virulence of YM001 were changed significantly as compared to the parental strain HN016. High doses of YM001 by intraperitoneal (IP) injection (1.0 × 10(9) CFU/fish) and oral gavage (1.0 × 10(10) CFU/fish) respectively did not cause any mortality and morbidity in tilapia. The relative percent survivals (RPSs) of fishes immunized with YM001 (1.0 × 10(8) CFU/fish, one time) via injection, immersion, and oral administration were 96.88, 67.22, and 71.81%, respectively, at 15 days, and 93.61, 60.56, and 53.16%, respectively, at 30 days. In all tests with 1-3 times of immunization in tilapia, the dosages at 1 × 10(8) and 1 × 10(9) CFU/fish displayed the similar best results, whereas the immunoprotection of the dosages at 1 × 10(6) and 1 × 10(7) CFU/fish declined significantly (P < 0.01), and 1 × 10(5) CFU/fish hardly displayed any protective effect. In addition, the efficacy of 2-3 times of immunization was significantly higher than that of single immunization (P < 0.01) while no significant difference in the efficacy between twice and thrice of immunization was seen (P > 0.05). The level of protective antibody elicited by oral immunization was significantly higher compared to that of the control group (P < 0.01), and the antibody reached their maximum levels 14-21 days after the immunization but decreased

  17. Molecular epidemiology and strain-specific characteristics of Streptococcus agalactiae at the herd and cow level.

    PubMed

    Mahmmod, Y S; Klaas, I C; Katholm, J; Lutton, M; Zadoks, R N

    2015-10-01

    Host-adaptation of Streptococcus agalactiae subpopulations has been described whereby strains that are commonly associated with asymptomatic carriage or disease in people differ phenotypically and genotypically from those causing mastitis in dairy cattle. Based on multilocus sequence typing (MLST), the most common strains in dairy herds in Denmark belong to sequence types (ST) that are also frequently found in people. The aim of this study was to describe epidemiological and diagnostic characteristics of such strains in relation to bovine mastitis. Among 1,199 cattle from 6 herds, cow-level prevalence of S. agalactiae was estimated to be 27.4% based on PCR and 7.8% based on bacteriological culture. Quarter-level prevalence was estimated at 2.8% based on bacteriological culture. Per herd, between 2 and 26 isolates were characterized by pulsed-field gel electrophoresis (PFGE) and MLST. Within each herd, a single PFGE type and ST predominated, consistent with a contagious mode of transmission or point source infection within herds. Evidence of within-herd evolution of S. agalactiae was detected with both typing methods, although ST belonged to a single clonal complex (CC) per herd. Detection of CC23 (3 herds) was associated with significantly lower approximate count (colony-forming units) at the quarter level and significantly lower cycle threshold value at the cow level than detection of CC1 (2 herds) or CC19 (1 herd), indicating a lower bacterial load in CC23 infections. Median values for the number of infected quarters and somatic cell count (SCC) were numerically but not significantly lower for cows infected with CC23 than for cows with CC1 or CC19. For all CC, an SCC threshold of 200,000 cells/mL was an unreliable indicator of infection status, and prescreening of animals based on SCC as part of S. agalactiae detection and eradication campaigns should be discouraged. PMID:26233443

  18. Evaluation of two herd-level diagnostic tests for Streptococcus agalactiae using a latent class approach.

    PubMed

    Mweu, Marshal M; Toft, Nils; Katholm, Jørgen; Nielsen, Søren S

    2012-09-14

    Streptococcus agalactiae mastitis persists as a significant economic problem for the dairy industry in many countries. In Denmark, the annual surveillance programme for this mastitis pathogen initially based only on bacteriological culture of bulk tank milk (BTM) samples, has recently incorporated the use of the real-time PathoProof Mastitis PCR assay with the goal of improving detection of infected herds. The objective of our study was to estimate the herd sensitivity (Se) and specificity (Sp) of both tests of BTM samples using latent class models in a Bayesian analysis while evaluating the effect of herd-level covariates on the Se and Sp of the tests. BTM samples were collected from all 4258 Danish dairy herds in 2009 and screened for the presence of S. agalactiae using both tests. The highest Se of PCR was realized at a cycle threshold (Ct) cut-off value of 40. At this cut-off, the Se of the PCR was significantly higher (95.2; 95% posterior credibility interval [PCI] [88.2; 99.8]) than that of bacteriological culture (68.0; 95% PCI [55.1; 90.0]). However, culture had higher Sp (99.7; 95% PCI [99.3; 100.0]) compared to PCR (98.8; 95% PCI [97.2; 99.9]). The accuracy of the tests was unaffected by the herd-level covariates. We propose that screenings of BTM samples for S. agalactiae be based on the PCR assay with Ct readings of <40 considered as positive. However, for higher Ct values, confirmation of PCR test positive herds by bacteriological culture is advisable especially when the between-herd prevalence of S. agalactiae is low. PMID:22542270

  19. Combination of selective enrichment and MALDI-TOF MS for rapid detection of Streptococcus agalactiae colonisation of pregnant women.

    PubMed

    Ábrók, Marianna; Arcson, Ágnes; Lázár, Andrea; Urbán, Edit; Deák, Judit

    2015-07-01

    Sample preparation was optimized for MALDI-TOF MS directly from selective enrichment broth to detect Streptococcus agalactiae. The method was tested on 100 vaginal samples of pregnant women; positive and negative predictive values were 100 and 91%, respectively. If it indicates positivity, colonisation can be reported 18-24h after sample collection.

  20. Crystallization and preliminary crystallographic analysis of two Streptococcus agalactiae proteins: the family II inorganic pyrophosphatase and the serine/threonine phosphatase

    SciTech Connect

    Rantanen, Mika K.; Lehtiö, Lari; Rajagopal, Lakshmi; Rubens, Craig E.; Goldman, Adrian

    2006-09-01

    Two S. agalactiae proteins, the inorganic pyrophosphatase and the serine/threonine phosphatase, were crystallized and diffraction data were collected and processed from these crystals. The data from the two protein crystals extended to 2.80 and 2.65 Å, respectively. Streptococcus agalactiae, which infects human neonates and causes sepsis and meningitis, has recently been shown to possess a eukaryotic-like serine/threonine protein phosphorylation signalling cascade. Through their target proteins, the S. agalactiae Ser/Thr kinase and Ser/Thr phosphatase together control the growth as well as the morphology and virulence of this organism. One of the targets is the S. agalactiae family II inorganic pyrophosphatase. The inorganic pyrophosphatase and the serine/threonine phosphatase have therefore been purified and crystallized and diffraction data have been collected from their crystals. The data were processed using XDS. The inorganic pyrosphosphatase crystals diffracted to 2.80 Å and the Ser/Thr phosphatase crystals to 2.65 Å. Initial structure-solution experiments indicate that structure solution will be successful in both cases. Solving the structure of the proteins involved in this cascade is the first step towards understanding this phenomenon in atomic detail.

  1. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of glyceraldehyde-3-phosphate dehydrogenase from Streptococcus agalactiae NEM316

    PubMed Central

    Nagarajan, Revathi; Ponnuraj, Karthe

    2014-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential enzyme involved in glycolysis. Despite lacking the secretory signal sequence, this cytosolic enzyme has been found localized at the surface of several bacteria and fungi. As a surface protein, GAPDH exhibits various adhesive functions, thereby facilitating colonization and invasion of host tissues. Streptococcus agalactiae, also known as group B streptococcus (GBS), binds onto the host using its surface adhesins and causes sepsis and pneumonia in neonates. GAPDH is one of the surface adhesins of GBS binding to human plasminogen and is a virulent factor associated with host colonization. Although the surface-associated GAPDH has been shown to bind to a variety of host extracellular matrix (ECM) molecules in various bacteria, the molecular mechanism underlying their interaction is not fully understood. To investigate this, structural studies on GAPDH of S. agalactiae were initiated. The gapC gene of S. agalactiae NEM316 encoding GAPDH protein was cloned into pET-28a vector, overexpressed in Escherichia coli BL21(DE3) cells and purified to homogeneity. The purified protein was crystallized using the hanging-drop vapour-diffusion method. The GAPDH crystals obtained in two different crystallization conditions diffracted to 2.8 and 2.6 Å resolution, belonging to two different space groups P21 and P212121, respectively. The structure was solved by molecular replacement and structure refinement is now in progress. PMID:25005093

  2. Nile Tilapia Infectivity by Genomically Diverse Streptoccocus agalactiae Isolates from Multiple Hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, Lancefield group B Streptococcus (GBS), is recognized for causing cattle mastitis, human neonatal meningitis, and fish meningo-encephalitis. We investigated the genomic diversity of GBS isolates from different phylogenetic hosts and geographical regions using serological t...

  3. Additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae and S. agalactiae capsular type Ib: is genetic resistance correlated?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus (S.) iniae and S. agalactiae are both economically important Gram positive bacterial pathogens affecting the globally farmed tilapia (Oreochromis spp.). Historically control of these bacteria in tilapia culture has included biosecurity, therapeutants and vaccination strategies. Genet...

  4. Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.

    PubMed

    Li, Wei; Wang, Hai-Qing; He, Run-Zhen; Li, Yan-Wei; Su, You-Lu; Li, An-Xing

    2016-08-01

    Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel

  5. Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.

    PubMed

    Li, Wei; Wang, Hai-Qing; He, Run-Zhen; Li, Yan-Wei; Su, You-Lu; Li, An-Xing

    2016-08-01

    Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel

  6. An Evaluation of a Teat Dip with Dodecyl Benzene Sulfonic Acid in Preventing Bovine Mammary Gland Infection from Experimental Exposure to Streptococcus agalactiae and Staphylococcus aureus

    PubMed Central

    Barnum, D. A.; Johnson, R. E.; Brooks, B. W.

    1982-01-01

    The effectiveness of a teat dip with dodecyl benzene sulfonic acid (1.94%) for the prevention of intramammary infections was determined in cows experimentally challenged with Streptococcus agalactiae and Staphylococcus aureus. The infection rates with Streptococcus agalactiae and Staphylococcus aureus were 62.5% and 75% in undipped quarters, 12.5% and 21.5% in dipped quarters with a reduction rate of 80% and 71% respectively. The significance of some findings in relation to mastitis control are discussed. PMID:17422110

  7. Efficacy of .18% iodine teat dip against Staphylococcus aureus and Streptococcus agalactiae.

    PubMed

    Boddie, R L; Nickerson, S C

    1989-04-01

    Effective postmilking teat dip products with lower iodine concentrations are being formulated as concern increases about iodine residues in milk. Increased free iodine concentration with greater germicidal activity in teat dip products is also possible with special formulation procedures. Low iodine concentration dips are cheaper and have reduced teat irritation. A concentrated iodine teat dip containing .18% iodine and 8 ppm free iodine upon dilution was evaluated under experimental bacterial challenge to determine efficacy for prevention of new intramammary infections. The undiluted product also contained 15% collagen protein emollient as a teat skin conditioner. Efficacy of the teat dip was 93.6 and 51. 7% for Staphylococcus aureus (Newbould 305) and Streptococcus agalactiae (McDonald 44). No adverse effects of the dip on teat skin were noted. PMID:2663939

  8. Pathological changes in red tilapias (Oreochromis spp.) naturally infected by Streptococcus agalactiae.

    PubMed

    Zamri-Saad, M; Amal, M N A; Siti-Zahrah, A

    2010-01-01

    The pathological changes present in 300 red tilapias (Oreochromis spp.) naturally infected by Streptococcus agalactiae are described. The most consistent gross findings were marked congestion of internal organs, particularly the liver, spleen and kidneys. Other features included exophthalmos, softening of the brain and the occasional accumulation of fluid within the abdominal cavity. Microscopical examination confirmed the presence of marked congestion of the liver, spleen and kidneys. The endothelial cells lining major blood vessels of the liver and occasionally the spleen were swollen and vacuolated. There was evidence of vascular thrombosis with infarction of surrounding tissue. Bacterial colonies were noted within and immediately surrounding the affected blood vessels. The meninges were thickened by the infiltration of numerous heterophils. Similar infiltrates of heterophils and lymphocytes were observed in the lamina propria of the intestine. The kidneys were severely congested and haemorrhagic, with extensive interstitial nephritis. PMID:20334871

  9. Efficacies of chlorine dioxide and lodophor teat dips during experimental challenge with Staphylococcus aureus and Streptococcus agalactiae.

    PubMed

    Boddie, R L; Nickerson, S C; Adkinson, R W

    2000-12-01

    We tested two postmilking teat dips for efficacy against Staphylococcus aureus and Streptococcus agalactiae using experimental challenge procedures recommended by the National Mastitis Council. The chlorine dioxide teat dip that contained 0.7% sodium chlorite reduced the number of new intramammary infections (IMI) caused by Staph. aureus by 86.6% and reduced new IMI caused by Strep. agalactiae by 88.4%. The 0.5% iodophor teat dip reduced the number of new IMI caused by Staph. aureus by 92.9% and reduced the number of new IMI caused by Strep. agalactiae by 43.4%. Teat skin and teat end conditions were evaluated before and after the study, and no deleterious effects were noted among dipped quarters compared with undipped control quarters for either teat dip. PMID:11132869

  10. Characterization and genome sequencing of a novel bacteriophage infecting Streptococcus agalactiae with high similarity to a phage from Streptococcus pyogenes.

    PubMed

    Bai, Qinqin; Zhang, Wei; Yang, Yongchun; Tang, Fang; Nguyen, Xuanhoa; Liu, Guangjin; Lu, Chengping

    2013-08-01

    A novel bacteriophage, JX01, specifically infecting bovine Streptococcus agalactiae was isolated from milk of mastitis-affected cattle. The phage morphology showed that JX01 belongs to the family Siphoviridae, and this phage demonstrated a broad host range. Microbiological characterization demonstrated that nearly 90 % of JX01 phage particles were adsorbed after 2.5 min of incubation, that the burst size was 20 virions released per infected host cell, and that there was a latent period of 30 min. JX01 was thermal sensitive and showed acid and alkaline resistance (pH 3-11). The genome of JX01 was found to consist of a linear, double-stranded 43,028-bp DNA molecule with a GC content of 36.81 % and 70 putative open reading frames (ORFs) plus one tRNA. Comparative genome analysis revealed high similarity between JX01 and the prophage 315.2 of Streptococcus pyogenes. PMID:23515875

  11. Development of a quantitative PCR assay for monitoring Streptococcus agalactiae colonization and tissue tropism in experimentally infected tilapia.

    PubMed

    Su, Y-L; Feng, J; Li, Y-W; Bai, J-S; Li, A-X

    2016-02-01

    Streptococcus agalactiae has become one of the most important emerging pathogens in the aquaculture industry and has resulted in large economic losses for tilapia farms in China. In this study, three pairs of specific primers were designed and tested for their specificities and sensitivities in quantitative real-time polymerase chain reactions (qPCRs) after optimization of the annealing temperature. The primer pair IGS-s/IGS-a, which targets the 16S-23S rRNA intergenic spacer region, was finally chosen, having a detection limit of 8.6 copies of S. agalactiae DNA in a 20 μL reaction mixture. Bacterial tissue tropism was demonstrated by qPCR in Oreochromis niloticus 5 days post-injection with a virulent S. agalactiae strain. Bacterial loads were detected at the highest level in brain, followed by moderately high levels in kidney, heart, spleen, intestines, and eye. Significantly lower bacterial loads were observed in muscle, gill and liver. In addition, significantly lower bacterial loads were observed in the brain of convalescent O. niloticus 14 days post-injection with several different S. agalactiae strains. The qPCR for the detection of S. agalactiae developed in this study provides a quantitative tool for investigating bacterial tissue tropism in infected fish, as well as for monitoring bacterial colonization in convalescent fish.

  12. Evaluation of Group B Streptococcus Differential Agar for detection and isolation of Streptococcus agalactiae.

    PubMed

    Bou, G; Figueira, M; Canle, D; Cartelle, M; Eiros, J M; Villanueva, R

    2005-08-01

    In total, 320 vaginal or rectal swabs were cultured on Granada medium (GM) or Group B Streptococcus Differential Agar (GBSDA), and were also inoculated into LIM broth (Todd-Hewitt broth supplemented with selective antibiotics), for detection of group B Streptococcus (GBS). Overall, GBS isolates were detected on 53 of the 320 swabs; 47 of these isolates grew on both GM and GBSDA, five only on GBSDA, and one only following subculture from LIM broth. GBSDA appears to be a valid alternative to GM for the growth of GBS isolates from pregnant women.

  13. Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae

    PubMed Central

    Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Atsushi

    2016-01-01

    Patient: Male, 74 Final Diagnosis: Infective endocarditis Symptoms: Apetite loss • fever Medication: — Clinical Procedure: Transesophageal echocardiography Specialty: Cardiology Objective: Rare co-existance of disease or pathology Background: Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). Case Report: A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient’s heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient’s condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. Conclusions: This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular

  14. Molecular Characterization of Streptococcus agalactiae Causing Community- and Hospital-Acquired Infections in Shanghai, China

    PubMed Central

    Jiang, Haoqin; Chen, Mingliang; Li, Tianming; Liu, Hong; Gong, Ye; Li, Min

    2016-01-01

    Streptococcus agalactiae, a colonizing agent in pregnant women and the main cause of neonatal sepsis and meningitis, has been increasingly associated with invasive disease in nonpregnant adults. We collected a total of 87 non-repetitive S. agalactiae isolates causing community-acquired (CA) and hospital-acquired (HA) infections in nonpregnant adults from a teaching hospital in Shanghai between 2009 and 2013. We identified and characterized their antibiotic resistance, sequence type (ST), serotype, virulence, and biofilm formation. The most frequent STs were ST19 (29.9%), ST23 (16.1%), ST12 (13.8%), and ST1 (12.6%). ST19 had significantly different distributions between CA- and HA-group B Streptococci (GBS) isolates. The most frequent serotypes were III (32.2%), Ia (26.4%), V (14.9%), Ib (13.8%), and II (5.7%). Serotype III/ST19 was significantly associated with levofloxacin resistance in all isoates. The HA-GBS multidrug resistant rate was much higher than that of CA-GBS. Virulence genes pavA, cfb were found in all isolates. Strong correlations exist between serotype Ib (CA and HA) and surface protein genes spb1 and bac, serotype III (HA) and surface protein gene cps and GBS pilus cluster. The serotype, epidemic clone, PFGE-based genotype, and virulence gene are closely related between CA-GBS and HA-GBS, and certain serotypes and clone types were significantly associated with antibiotic resistance. However, CA-GBS and HA-GBS still had significant differences in their distribution of clone types, antibiotic resistance, and specific virulence genes, which may provide a basis for infection control. PMID:27625635

  15. Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae.

    PubMed

    Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Astushi

    2016-01-01

    BACKGROUND Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). CASE REPORT A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient's heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient's condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. CONCLUSIONS This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular extension of the infection, which can lead to fatal heart block. PMID:27604147

  16. Molecular Characterization of Streptococcus agalactiae Causing Community- and Hospital-Acquired Infections in Shanghai, China

    PubMed Central

    Jiang, Haoqin; Chen, Mingliang; Li, Tianming; Liu, Hong; Gong, Ye; Li, Min

    2016-01-01

    Streptococcus agalactiae, a colonizing agent in pregnant women and the main cause of neonatal sepsis and meningitis, has been increasingly associated with invasive disease in nonpregnant adults. We collected a total of 87 non-repetitive S. agalactiae isolates causing community-acquired (CA) and hospital-acquired (HA) infections in nonpregnant adults from a teaching hospital in Shanghai between 2009 and 2013. We identified and characterized their antibiotic resistance, sequence type (ST), serotype, virulence, and biofilm formation. The most frequent STs were ST19 (29.9%), ST23 (16.1%), ST12 (13.8%), and ST1 (12.6%). ST19 had significantly different distributions between CA- and HA-group B Streptococci (GBS) isolates. The most frequent serotypes were III (32.2%), Ia (26.4%), V (14.9%), Ib (13.8%), and II (5.7%). Serotype III/ST19 was significantly associated with levofloxacin resistance in all isoates. The HA-GBS multidrug resistant rate was much higher than that of CA-GBS. Virulence genes pavA, cfb were found in all isolates. Strong correlations exist between serotype Ib (CA and HA) and surface protein genes spb1 and bac, serotype III (HA) and surface protein gene cps and GBS pilus cluster. The serotype, epidemic clone, PFGE-based genotype, and virulence gene are closely related between CA-GBS and HA-GBS, and certain serotypes and clone types were significantly associated with antibiotic resistance. However, CA-GBS and HA-GBS still had significant differences in their distribution of clone types, antibiotic resistance, and specific virulence genes, which may provide a basis for infection control.

  17. Molecular Characterization of Streptococcus agalactiae Causing Community- and Hospital-Acquired Infections in Shanghai, China.

    PubMed

    Jiang, Haoqin; Chen, Mingliang; Li, Tianming; Liu, Hong; Gong, Ye; Li, Min

    2016-01-01

    Streptococcus agalactiae, a colonizing agent in pregnant women and the main cause of neonatal sepsis and meningitis, has been increasingly associated with invasive disease in nonpregnant adults. We collected a total of 87 non-repetitive S. agalactiae isolates causing community-acquired (CA) and hospital-acquired (HA) infections in nonpregnant adults from a teaching hospital in Shanghai between 2009 and 2013. We identified and characterized their antibiotic resistance, sequence type (ST), serotype, virulence, and biofilm formation. The most frequent STs were ST19 (29.9%), ST23 (16.1%), ST12 (13.8%), and ST1 (12.6%). ST19 had significantly different distributions between CA- and HA-group B Streptococci (GBS) isolates. The most frequent serotypes were III (32.2%), Ia (26.4%), V (14.9%), Ib (13.8%), and II (5.7%). Serotype III/ST19 was significantly associated with levofloxacin resistance in all isoates. The HA-GBS multidrug resistant rate was much higher than that of CA-GBS. Virulence genes pavA, cfb were found in all isolates. Strong correlations exist between serotype Ib (CA and HA) and surface protein genes spb1 and bac, serotype III (HA) and surface protein gene cps and GBS pilus cluster. The serotype, epidemic clone, PFGE-based genotype, and virulence gene are closely related between CA-GBS and HA-GBS, and certain serotypes and clone types were significantly associated with antibiotic resistance. However, CA-GBS and HA-GBS still had significant differences in their distribution of clone types, antibiotic resistance, and specific virulence genes, which may provide a basis for infection control. PMID:27625635

  18. Efficacy of spray administration of formalin-killed Streptococcus agalactiae in hybrid Red Tilapia.

    PubMed

    Noraini, O; Sabri, M Y; Siti-Zahrah, A

    2013-06-01

    An initial evaluation of spray vaccination was carried out with 60 hybrid Red Tilapia Oreochromis spp., divided into three groups that consisted of 10 fish per group with duplicates. The formalin-killed cells (FKCs) of Streptococcus agalactiae were administered once to group 1 by spray and once daily for five consecutive days to group 2. Group 3 remained as the untreated control group and was sprayed with normal saline. A booster was given twice to all the groups, once at the second week and again at the fourth week after the first vaccination. After this initial evaluation, a challenge study was conducted with 40 tilapia divided into two groups that consisted of 10 fish per group with duplicates. Group 1 was vaccinated with FKCs of S. agalactiae by a single spray administration while group 2 remained as the untreated control group. A booster was given twice using the same protocol as in the initial evaluation. After 6 weeks, fish from one of the duplicate tanks from each of groups 1 and 2 were challenged with pathogenic S. agalactiae by intraperitoneal (IP) injection, while fish in another tank were challenged through immersion. Based on the observations, serum immunoglobulin M (IgM) levels were significantly higher (P < 0.05) in the challenged fish than in the either the preexposed fish or the control group 1 week after the initial exposure. However, no significant differences (P > 0.05) were noted between challenged groups 1 and 2. In addition, no significant differences (P > 0.05) were observed between the frequencies of exposure. The mucus IgM level, however, remained high after each booster until the end of the 8-week study period. Meanwhile, serum IgM levels decreased after the challenge. A higher percentage of survival was noted for fish challenged through immersion (80%) compared with IP injection (70%). These results suggested that single spray exposure was able to induce IgM, which gave moderate to high protection during the challenge study. PMID

  19. High Incidence of Macrolide and Tetracycline Resistance among Streptococcus Agalactiae Strains Isolated from Clinical Samples in Tehran, Iran

    PubMed Central

    EMANEINI, Mohammad; MIRSALEHIAN, Akbar; BEIGVIERDI, Reza; FOOLADI, Abbas Ali Imani; ASADI, Fatemeh; JABALAMELI, Fereshteh; TAHERIKALANI, Morovat

    2014-01-01

    Background: Streptococcus agalactiae or Group B Streptococci (GBS) is an important bacterial pathogen that causes a wide range of infections including neonatal sepsis, meningitis, pneumonia and soft tissue or urinary tract infections. Material and methods: One hundred and fifteen isolates of Streptococcus agalactiae collected from urine specimens of patients attending a hospital in Tehran. All isolates were screened for their capsular types and genes encoding resistance to the macrolide and tetracycline antibiotics by PCR and multiplex PCR–based methods. Results: Most of isolates belonged to capsular types III (49%), V (19%), II (16%), and Ib (6%). Twelve isolates (10%) were nontypable. All isolates were susceptible to penicillin and Quinupristin-dalfopristin, but were resistant to clindamycin (35%), chloramphenicol (45%), erythromycin (35%), linezolid (1%) and tetracycline (96%). The most prevalent antimicrobial resistance gene was tetM found in 93% of the isolates followed by ermTR, ermB, and tetK, found in 23%, 16%, and 16% of isolates, respectively. The genes, tetL, tetO, ermA, ermC and mefA were not detected in any of the S. agalactiae isolates. Of the 110 tetracycline resistant S. agalactiae, 89 isolates harbored the tetM gene alone and eighteen isolates carried the tetM gene with the tetK gene. All erythromycin-resistant isolates exhibited cMLSB resistance phenotype, 22 isolates harbored the ermTR gene alone and five isolates carried the ermTR gene with the ermB gene. The rate of coexistence of genes encoding the erythromycin and tetracycline resistance determinants was 34%. Conclusion: The present study demonstrated that S. agalactiae isolates obtained from urine samples showed a high rate of resistance to tetracycline, chloramphenicol and macrolide antibiotics and were commonly associated with the resistance genes temM, ermTR or ermB. PMID:25705271

  20. Spatiotemporal patterns, annual baseline and movement-related incidence of Streptococcus agalactiae infection in Danish dairy herds: 2000-2009.

    PubMed

    Mweu, Marshal M; Nielsen, Søren S; Halasa, Tariq; Toft, Nils

    2014-02-01

    Several decades after the inception of the five-point plan for the control of contagious mastitis pathogens, Streptococcus agalactiae (S. agalactiae) persists as a fundamental threat to the dairy industry in many countries. A better understanding of the relative importance of within- and between-herd sources of new herd infections coupled with the spatiotemporal distribution of the infection, may aid in effective targeting of control efforts. Thus, the objectives of this study were: (1) to describe the spatiotemporal patterns of infection with S. agalactiae in the population of Danish dairy herds from 2000 to 2009 and (2) to estimate the annual herd-level baseline and movement-related incidence risks of S. agalactiae infection over the 10-year period. The analysis involved registry data on bacteriological culture of all bulk tank milk samples collected as part of the mandatory Danish S. agalactiae surveillance scheme as well as live cattle movements into dairy herds during the specified 10-year period. The results indicated that the predicted risk of a herd becoming infected with S. agalactiae varied spatiotemporally; the risk being more homogeneous and higher in the period after 2005. Additionally, the annual baseline risks yielded significant yet distinctive patterns before and after 2005 - the risk of infection being higher in the latter phase. On the contrary, the annual movement-related risks revealed a non-significant pattern over the 10-year period. There was neither evidence for spatial clustering of cases relative to the population of herds at risk nor spatial dependency between herds. Nevertheless, the results signal a need to beef up within-herd biosecurity in order to reduce the risk of new herd infections. PMID:24269038

  1. Development of a loop-mediated isothermal amplification assay for the detection of Streptococcus agalactiae in bovine milk.

    PubMed

    Bosward, Katrina L; House, John K; Deveridge, Amber; Mathews, Karen; Sheehy, Paul A

    2016-03-01

    Streptococcus agalactiae is a well-characterized bovine mastitis pathogen that is known to be highly contagious and capable of spreading rapidly in affected dairy herds. Loop-mediated isothermal amplification (LAMP) is a novel molecular diagnostic method that has the capability to provide rapid, cost-effective screening for pathogens to support on-farm disease control and eradication programs. In the current study, a LAMP test was developed to detect S. agalactiae in milk. The assay was validated on a bank of existing clinical mastitis milk samples that had previously been identified as S. agalactiae positive via traditional microbiological culture techniques and PCR. The LAMP assay was conducted on bacterial colonies and DNA extracted from milk in tube- and plate-based formats using multiple detection platforms. The 1-h assay conducted at 64 °C exhibited repeatability (coefficient of variation) of 2.07% (tube) and 8.3% (plate), sensitivity to ~20 pg of extracted DNA/reaction, and specificity against a panel of known bacterial mastitis pathogens. Of the 109 known S. agalactiae isolates assessed by LAMP directly from bacterial cells in culture, 108 were identified as positive, in accordance with PCR analysis. The LAMP analysis from the corresponding milk samples indicated that 104 of these milks exhibited a positive amplification curve. Although exhibiting some limitations, this assay provides an opportunity for rapid screening of milk samples to facilitate on-farm management of this pathogen. PMID:26778303

  2. vanG Element Insertions within a Conserved Chromosomal Site Conferring Vancomycin Resistance to Streptococcus agalactiae and Streptococcus anginosus

    PubMed Central

    Srinivasan, Velusamy; Metcalf, Benjamin J.; Knipe, Kristen M.; Ouattara, Mahamoudou; McGee, Lesley; Shewmaker, Patricia L.; Glennen, Anita; Nichols, Megin; Harris, Carol; Brimmage, Mary; Ostrowsky, Belinda; Park, Connie J.; Schrag, Stephanie J.; Frace, Michael A.; Sammons, Scott A.

    2014-01-01

    ABSTRACT Three vancomycin-resistant streptococcal strains carrying vanG elements (two invasive Streptococcus agalactiae isolates [GBS-NY and GBS-NM, both serotype II and multilocus sequence type 22] and one Streptococcus anginosus [Sa]) were examined. The 45,585-bp elements found within Sa and GBS-NY were nearly identical (together designated vanG-1) and shared near-identity over an ~15-kb overlap with a previously described vanG element from Enterococcus faecalis. Unexpectedly, vanG-1 shared much less homology with the 49,321-bp vanG-2 element from GBS-NM, with widely different levels (50% to 99%) of sequence identity shared among 44 related open reading frames. Immediately adjacent to both vanG-1 and vanG-2 were 44,670-bp and 44,680-bp integrative conjugative element (ICE)-like sequences, designated ICE-r, that were nearly identical in the two group B streptococcal (GBS) strains. The dual vanG and ICE-r elements from both GBS strains were inserted at the same position, between bases 1328 and 1329, within the identical RNA methyltransferase (rumA) genes. A GenBank search revealed that although most GBS strains contained insertions within this specific site, only sequence type 22 (ST22) GBS strains contained highly related ICE-r derivatives. The vanG-1 element in Sa was also inserted within this position corresponding to its rumA homolog adjacent to an ICE-r derivative. vanG-1 insertions were previously reported within the same relative position in the E. faecalis rumA homolog. An ICE-r sequence perfectly conserved with respect to its counterpart in GBS-NY was apparent within the same site of the rumA homolog of a Streptococcus dysgalactiae subsp. equisimilis strain. Additionally, homologous vanG-like elements within the conserved rumA target site were evident in Roseburia intestinalis. PMID:25053786

  3. vanG element insertions within a conserved chromosomal site conferring vancomycin resistance to Streptococcus agalactiae and Streptococcus anginosus.

    PubMed

    Srinivasan, Velusamy; Metcalf, Benjamin J; Knipe, Kristen M; Ouattara, Mahamoudou; McGee, Lesley; Shewmaker, Patricia L; Glennen, Anita; Nichols, Megin; Harris, Carol; Brimmage, Mary; Ostrowsky, Belinda; Park, Connie J; Schrag, Stephanie J; Frace, Michael A; Sammons, Scott A; Beall, Bernard

    2014-01-01

    Three vancomycin-resistant streptococcal strains carrying vanG elements (two invasive Streptococcus agalactiae isolates [GBS-NY and GBS-NM, both serotype II and multilocus sequence type 22] and one Streptococcus anginosus [Sa]) were examined. The 45,585-bp elements found within Sa and GBS-NY were nearly identical (together designated vanG-1) and shared near-identity over an ~15-kb overlap with a previously described vanG element from Enterococcus faecalis. Unexpectedly, vanG-1 shared much less homology with the 49,321-bp vanG-2 element from GBS-NM, with widely different levels (50% to 99%) of sequence identity shared among 44 related open reading frames. Immediately adjacent to both vanG-1 and vanG-2 were 44,670-bp and 44,680-bp integrative conjugative element (ICE)-like sequences, designated ICE-r, that were nearly identical in the two group B streptococcal (GBS) strains. The dual vanG and ICE-r elements from both GBS strains were inserted at the same position, between bases 1328 and 1329, within the identical RNA methyltransferase (rumA) genes. A GenBank search revealed that although most GBS strains contained insertions within this specific site, only sequence type 22 (ST22) GBS strains contained highly related ICE-r derivatives. The vanG-1 element in Sa was also inserted within this position corresponding to its rumA homolog adjacent to an ICE-r derivative. vanG-1 insertions were previously reported within the same relative position in the E. faecalis rumA homolog. An ICE-r sequence perfectly conserved with respect to its counterpart in GBS-NY was apparent within the same site of the rumA homolog of a Streptococcus dysgalactiae subsp. equisimilis strain. Additionally, homologous vanG-like elements within the conserved rumA target site were evident in Roseburia intestinalis. Importance: These three streptococcal strains represent the first known vancomycin-resistant strains of their species. The collective observations made from these strains reveal a specific

  4. Streptococcus agalactiae: prevalence of antimicrobial resistance in vaginal and rectal swabs in Italian pregnant women.

    PubMed

    Matani, Chiara; Trezzi, Michele; Matteini, Alice; Catalani, Carlotta; Messeri, Daniela; Catalani, Corrado

    2016-09-01

    Intrapartum antibiotic prophylaxis (IAP) reduces both the vertical transmission of Streptococcus agalactiae or Group B Streptococcus (GBS) and the early onset of neonatal sepsis. However, existing guidelines do not recommend that antimicrobial susceptibility testing (AST) be routinely performed. Penicillin or ampicillin are indicated as first-choice antibiotics, cefazolin being an alternative in the case of history of mild allergic reactions, and vancomycin or clindamycin an alternative in the event of severe reactions. We performed a cross-sectional analysis to identify the presence of any bacterial resistance towards the antibiotics most frequently used for IAP in pregnant women with GBS positive vaginal-rectal swabs, in the Pistoia area of central Italy. Of the 255 tested samples, 65 (25.5%) were positive for GBS. Sensitivity to glycopeptides was over 90%, but lower to ampicillin and penicillin (87.10% and 87.93% respectively). Resistance towards clindamycin and erythromycin was as high as 43.75% and 32.20%. All tested GBS proved susceptible to moxifloxacin, linezolid and tigecycline. Our observed prevalence is aligned or slightly higher than data reported in other series. The less than full effectiveness and low percentages of ampicillin and penicillin sensitivity observed give cause for concern. We confirmed the increase in clindamycin and erythromycin resistance. Glycopeptides can be used as second-line antibiotics, but the complete AST of GBS should always be performed before IAP. Given that gentamicin is used synergically with penicillin when treating chorioamnionitis, it needs to be always included in the AST. This is the first study on the GBS sensitivity profile in Tuscany. Further investigation on a larger scale is required prior to implementing any changes in the current guidelines. PMID:27668902

  5. Maternal colonization with Streptococcus agalactiae and associated stillbirth and neonatal disease in coastal Kenya.

    PubMed

    Seale, Anna C; Koech, Angela C; Sheppard, Anna E; Barsosio, Hellen C; Langat, Joyce; Anyango, Emily; Mwakio, Stella; Mwarumba, Salim; Morpeth, Susan C; Anampiu, Kirimi; Vaughan, Alison; Giess, Adam; Mogeni, Polycarp; Walusuna, Leahbell; Mwangudzah, Hope; Mwanzui, Doris; Salim, Mariam; Kemp, Bryn; Jones, Caroline; Mturi, Neema; Tsofa, Benjamin; Mumbo, Edward; Mulewa, David; Bandika, Victor; Soita, Musimbi; Owiti, Maureen; Onzere, Norris; Walker, A Sarah; Schrag, Stephanie J; Kennedy, Stephen H; Fegan, Greg; Crook, Derrick W; Berkley, James A

    2016-01-01

    Streptococcus agalactiae (group B streptococcus, GBS) causes neonatal disease and stillbirth, but its burden in sub-Saharan Africa is uncertain. We assessed maternal recto-vaginal GBS colonization (7,967 women), stillbirth and neonatal disease. Whole-genome sequencing was used to determine serotypes, sequence types and phylogeny. We found low maternal GBS colonization prevalence (934/7,967, 12%), but comparatively high incidence of GBS-associated stillbirth and early onset neonatal disease (EOD) in hospital (0.91 (0.25-2.3)/1,000 births and 0.76 (0.25-1.77)/1,000 live births, respectively). However, using a population denominator, EOD incidence was considerably reduced (0.13 (0.07-0.21)/1,000 live births). Treated cases of EOD had very high case fatality (17/36, 47%), especially within 24 h of birth, making under-ascertainment of community-born cases highly likely, both here and in similar facility-based studies. Maternal GBS colonization was less common in women with low socio-economic status, HIV infection and undernutrition, but when GBS-colonized, they were more probably colonized by the most virulent clone, CC17. CC17 accounted for 267/915 (29%) of maternal colonizing (265/267 (99%) serotype III; 2/267 (0.7%) serotype IV) and 51/73 (70%) of neonatal disease cases (all serotype III). Trivalent (Ia/II/III) and pentavalent (Ia/Ib/II/III/V) vaccines would cover 71/73 (97%) and 72/73 (99%) of disease-causing serotypes, respectively. Serotype IV should be considered for inclusion, with evidence of capsular switching in CC17 strains. PMID:27572968

  6. Uncaria tomentosa increases growth and immune activity in Oreochromis niloticus challenged with Streptococcus agalactiae.

    PubMed

    Yunis-Aguinaga, Jefferson; Claudiano, Gustavo S; Marcusso, Paulo F; Manrique, Wilson Gómez; de Moraes, Julieta R Engrácia; de Moraes, Flávio R; Fernandes, João B K

    2015-11-01

    Cat's claw (Uncaria tomentosa) is an Amazon herb using in native cultures in Peru. In mammals, it has been described several effects of this herb. However, this is the first report of its use on the diet of fish. The aim of this study was to determinate the effect of this plant on the growth and immune activity in Oreochromis niloticus. Nile tilapia (81.3 ± 4.5 g) were distributed into 5 groups and supplemented with 0 (non-supplement fish), 75, 150, 300, and 450 mg of U. tomentosa.kg(-1) of diet for a period of 28 days. Fish were inoculated in the swim bladder with inactivated Streptococcus agalactiae and samples were taken at 6, 24, and 48 h post inoculation (HPI). Dose dependent increases were noted in some of the evaluated times of thrombocytes and white blood cells counts (WBC) in blood and exudate, burst respiratory activity, lysozyme activity, melanomacrophage centers count (MMCs), villi length, IgM by immunohistochemistry in splenic tissue, and unexpectedly on growth parameters. However, dietary supplementation of this herb did not affect red blood cells count (RBC), hemoglobin, and there were no observed histological lesions in gills, intestine, spleen, and liver. The current results demonstrate for the first time that U. tomentosa can stimulate fish immunity and improve growth performance in Nile tilapia.

  7. Effect of Eugenol against Streptococcus agalactiae and Synergistic Interaction with Biologically Produced Silver Nanoparticles.

    PubMed

    Perugini Biasi-Garbin, Renata; Saori Otaguiri, Eliane; Morey, Alexandre Tadachi; Fernandes da Silva, Mayara; Belotto Morguette, Ana Elisa; Armando Contreras Lancheros, César; Kian, Danielle; Perugini, Márcia Regina Eches; Nakazato, Gerson; Durán, Nelson; Nakamura, Celso Vataru; Yamauchi, Lucy Megumi; Yamada-Ogatta, Sueli Fumie

    2015-01-01

    Streptococcus agalactiae (group B streptococci (GBS)) is an important infections agent in newborns associated with maternal vaginal colonization. Intrapartum antibiotic prophylaxis in GBS-colonized pregnant women has led to a significant reduction in the incidence of early neonatal infection in various geographic regions. However, this strategy may lead to resistance selecting among GBS, indicating the need for new alternatives to prevent bacterial transmission and even to treat GBS infections. This study reported for the first time the effect of eugenol on GBS isolated from colonized women, alone and in combination with silver nanoparticles produced by Fusarium oxysporum (AgNPbio). Eugenol showed a bactericidal effect against planktonic cells of all GBS strains, and this effect appeared to be time-dependent as judged by the time-kill curves and viability analysis. Combination of eugenol with AgNPbio resulted in a strong synergistic activity, significantly reducing the minimum inhibitory concentration values of both compounds. Scanning and transmission electron microscopy revealed fragmented cells and changes in bacterial morphology after incubation with eugenol. In addition, eugenol inhibited the viability of sessile cells during biofilm formation and in mature biofilms. These results indicate the potential of eugenol as an alternative for controlling GBS infections.

  8. Structural basis of lantibiotic recognition by the nisin resistance protein from Streptococcus agalactiae

    PubMed Central

    Khosa, Sakshi; Frieg, Benedikt; Mulnaes, Daniel; Kleinschrodt, Diana; Hoeppner, Astrid; Gohlke, Holger; Smits, Sander H. J.

    2016-01-01

    Lantibiotics are potent antimicrobial peptides. Nisin is the most prominent member and contains five crucial lanthionine rings. Some clinically relevant bacteria express membrane-associated resistance proteins that proteolytically inactivate nisin. However, substrate recognition and specificity of these proteins is unknown. Here, we report the first three-dimensional structure of a nisin resistance protein from Streptococcus agalactiae (SaNSR) at 2.2 Å resolution. It contains an N-terminal helical bundle, and protease cap and core domains. The latter harbors the highly conserved TASSAEM region, which lies in a hydrophobic tunnel formed by all domains. By integrative modeling, mutagenesis studies, and genetic engineering of nisin variants, a model of the SaNSR/nisin complex is generated, revealing that SaNSR recognizes the last C-terminally located lanthionine ring of nisin. This determines the substrate specificity of SaNSR and ensures the exact coordination of the nisin cleavage site at the TASSAEM region. PMID:26727488

  9. Characterization and antibiotic susceptibility of Streptococcus agalactiae isolates causing urinary tract infections.

    PubMed

    Piccinelli, Giorgio; Biscaro, Valeria; Gargiulo, Franco; Caruso, Arnaldo; De Francesco, Maria Antonia

    2015-08-01

    Streptococcus agalactiae (GBS) has been implicated in urinary tract infections but the microbiological characteristics and antimicrobial susceptibility of these strains are poorly investigated. In this study, 87 isolates recovered from urine samples of patients who had attended the Spedali Civili of Brescia (Italy) and had single organism GBS cultured were submitted to antimicrobial susceptibility testing, molecular characterization of macrolide and levofloxacin resistance, PCR-based capsular typing and analysis of surface protein genes. By automated broth microdilution method, all isolates were susceptible to penicillin, cefuroxime, cefaclor, and ceftriaxone; 80%, 19.5% and 3.4% of isolates were non-susceptible to tetracycline, erythromycin, and levofloxacin, respectively. Macrolide resistance determinants were iMLS(B) (n=1), cMLS(B) (n=10) and M (n=5), associated with ermTR, ermB and mefA/E. Levofloxacin resistance was linked to mutations in gyrA and parC genes. Predominant capsular types were III, Ia, V, Ib and IX. Type III was associated with tetracycline resistance, while type Ib was associated with levofloxacin resistance. Different capsular type-surface protein gene combinations (serotype V-alp2, 3; serotype III-rib; serotype Ia-epsilon) were detected. A variety of capsular types are involved in significant bacteriuria. The emergence of multidrug resistant GBS may become a significant public health concern and highlights the importance of careful surveillance to prevent the emergence of these virulent GBS. PMID:26144658

  10. Méningo-encéphalite à Streptococcus agalactiae chez l'adulte non immunodéprimé

    PubMed Central

    Rafai, Mostafa; Chouaib, Naoufal; Zidouh, Saad; Bakkali, Hicham; Belyamani, Lahcen

    2015-01-01

    Streptococcus agalactiae est un Streptocoque beta-hémolytique du groupe B (SGB), c'est un germe commensal occasionnel de la peau, du tube digestif et des voies génito-urinaires. Nous rapportons un cas inhabituel d'une méningo-encéphalite due au Streptococcus agalactiae (SGB) multisensible à l'antibiogramme chez un sujet adulte immunocompétent admis au service des urgences pour prise en charge de troubles de conscience fébrile. L’évolution clinique et biologique à J10 était favorable et le patient à été transféré au service de neurologie pour complément de prise en charge secondaire. L'originalité de notre observation réside dans la rareté du type d'infection par ce germe puise qu'elle est la troisième à notre connaissance d'une méningo-encéphalite à Streptococcus agalactiae dans la littérature, c'est ainsi que même s'il est très rarement en cause, il doit être considéré comme une étiologie possible de méningo-encéphalite chez l'adulte en dehors de la grossesse, quelle que soit le statut immunitaire du patient, et sans méconnaitre le rôle du terrain sous-jacent dans l’émergence de cette pathologie infectieuse polymorphe est potentiellement grave. PMID:25995802

  11. A commercial rapid optical immunoassay detects Streptococcus agalactiae from aquatic cultures and clinical specimens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The BioStar STREPT B Optical ImmunoAssay (OIA) (BioStar® OIA® Strep B Assay Kit; Biostar Incorporation; Louisville, CO, USA) was used to identify 32 known group B streptococcus (GBS) isolates of fish, dolphin, bovine, and human origin. Thirteen non-GBS isolates from fish and other animals were test...

  12. Glucose degradation, molar growth yields, and evidence for oxidative phosphorylation in Streptococcus agalactiae.

    PubMed

    Mickelson, M N

    1972-01-01

    In a complex medium with the energy source as the limiting nutrient factor and under anaerobic growth conditions, Streptococcus agalactiae fermented 75% of the glucose to lactic acid and the remainder to acetic and formic acids and ethanol. By using the adenosine triphosphate (ATP) yield constant of 10.5, the molar growth yield suggested 2 moles of ATP per mole of glucose from substrate level phosphorylation. Under similar growth conditions, pyruvate was fermented 25% to lactic acid, and the remainder was fermented to acetic and formic acids. The molar growth yield suggested 0.75 mole of ATP per mole of pyruvate from substrate level phosphorylation. Under aerobic growth conditions about 1 mole of oxygen was consumed per mole of glucose; about one-third of the glucose was converted to lactic acid and the remainder to acetic acid, acetoin, and carbon dioxide. Molar growth yields indicated 5 moles of ATP per mole of glucose. Estimates based on products of glucose degradation suggested that about one-half of the ATP was derived from substrate level phosphorylation and one-half from oxidative phosphorylation. Addition of 0.5 m 2,4-dinitrophenol reduced the growth yield to that occurring in the absence of oxygen. Aerobic pyruvate degradation resulted in 30% of the substrate becoming reduced to lactic acid and the remainder being converted to acetic acid and carbon dioxide, with small amounts of formic acid and acetoin. The molar growth yields and products found suggested that 0.70 mole of ATP per mole of pyruvate resulted from substrate level phosphorylation and 0.4 mole per mole of pyruvate resulted from oxidative phosphorylation.

  13. Short communication: Lipolytic activity on milk fat by Staphylococcus aureus and Streptococcus agalactiae strains commonly isolated in Swedish dairy herds.

    PubMed

    Vidanarachchi, Janak K; Li, Shengjie; Lundh, Åse Sternesjö; Johansson, Monika

    2015-12-01

    The objective of this study was to determine the lipolytic activity on milk fat of 2 bovine mastitis pathogens, that is, Staphylococcus aureus and Streptococcus agalactiae. The lipolytic activity was determined by 2 different techniques, that is, thin-layer chromatography and an extraction-titration method, in an experimental model using the most commonly occurring field strains of the 2 mastitic bacteria isolated from Swedish dairy farms. The microorganisms were inoculated into bacteria-free control milk and incubated at 37°C to reflect physiological temperatures in the mammary gland. Levels of free fatty acids (FFA) were analyzed at time of inoculation (t=0) and after 2 and 6h of incubation, showing significant increase in FFA levels. After 2h the FFA content had increased by approximately 40% in milk samples inoculated with Staph. aureus and Strep. agalactiae, and at 6h the pathogens had increased FFA levels by 47% compared with the bacteria-free control milk. Changes in lipid composition compared with the bacteria-free control were investigated at 2 and 6h of incubation. Diacylglycerols, triacylglycerols, and phospholipids increased significantly after 6h incubation with the mastitis bacteria, whereas cholesterol and sterol esters decreased. Our results suggest that during mammary infections with Staph. aureus and Strep. agalactiae, the action of lipases originating from the mastitis pathogens will contribute significantly to milk fat lipolysis and thus to raw milk deterioration.

  14. Evaluation of the efficacy of intramuscular versus intramammary treatment of subclinical Streptococcus agalactiae mastitis in dairy cows in Colombia.

    PubMed

    Reyes, J; Chaffer, M; Sanchez, J; Torres, G; Macias, D; Jaramillo, M; Duque, P C; Ceballos, A; Keefe, G P

    2015-08-01

    A randomized controlled trial was performed in 17 Colombian dairy herds to determine the cure risk among cows subclinically infected with Streptococcus agalactiae exposed to 2 antibiotic therapies. Composite milk samples were collected before milking at the onset of the trial (pretreatment) and 2 subsequent times over a period of approximately 63 d. The intramammary application (IMM) of ampicillin-cloxacillin was compared with the intramuscular application (IM) of penethamate hydriodide, and cure risks after an initial and retreatment application were assessed. Cure risk after the initial treatment was higher (82.4%) for the IMM treatment than for IM therapy (65.8%). However, no difference was observed in the cure risk of refractory cases after retreatment (IMM=52.6% vs. IM=51.2%). The cumulative cure risk (both initial and retreatment) was 90.4 and 82.9% for the IMM and IM products, respectively. A 2-level random effects logistic model that controlled for pretreatment cow-level somatic cell count, indicated that IM treatment (odds ratio=0.37) had a lower cure risk than IMM and a tendency for a lower cure risk with increasing baseline somatic cell count. Our findings suggest that both products and administration routes can reduce the prevalence of S. agalactiae in affected herds, but the IMM product had a better efficacy in curing the infection. In addition to the treatment protocol, the cow somatic cell count should be considered when making management decisions for cows infected with S. agalactiae. PMID:26074229

  15. Molecular and bacteriological investigation of subclinical mastitis caused by Staphylococcus aureus and Streptococcus agalactiae in domestic bovids from Ismailia, Egypt.

    PubMed

    Elhaig, Mahmoud Mohey; Selim, Abdelfattah

    2015-02-01

    A study was carried out to establish the prevalence of subclinical mastitis (SCM) in smallholder dairy farms in Ismailia, Egypt. A total of 340 milking cows and buffaloes were sampled from 60 farms, and 50 nasal swabs were collected from consenting farm workers. Milk samples were subjected to California mastitis test (CMT) and the positive samples were examined by bacterial culture and PCR to identify etiological agents. Based on CMT, the prevalence of SCM was 71.6 % in cattle and 43.5 % in buffaloes while the prevalence was 25.2 % at cow-quarter level and 21.7 % at buffaloes-quarter level. Bacteriological analysis showed that the most frequently identified bacteria were Staphylococcus (S.) aureus (38.3 %) and Streptococcus (Str.) agalactiae (20 %). The diagnostic sensitivity of PCR compared to bacterial culture was superior with S. aureus and Str. agalactiae detection being 41 and 22.6 %, respectively. Furthermore, methicillin-resistant S. aureus (MRSA) strains occurred in 52.2 and 45 % of isolates of animals and workers, respectively. Subclinical mastitis due to S. aureus and Str. agalactiae is endemic in smallholder dairy herds in Ismailia. The occurrence of MRSA in animals and workers highlights a need for wide epidemiological studies of MRSA and adopting control strategies. PMID:25374070

  16. Short communication: Lipolytic activity on milk fat by Staphylococcus aureus and Streptococcus agalactiae strains commonly isolated in Swedish dairy herds.

    PubMed

    Vidanarachchi, Janak K; Li, Shengjie; Lundh, Åse Sternesjö; Johansson, Monika

    2015-12-01

    The objective of this study was to determine the lipolytic activity on milk fat of 2 bovine mastitis pathogens, that is, Staphylococcus aureus and Streptococcus agalactiae. The lipolytic activity was determined by 2 different techniques, that is, thin-layer chromatography and an extraction-titration method, in an experimental model using the most commonly occurring field strains of the 2 mastitic bacteria isolated from Swedish dairy farms. The microorganisms were inoculated into bacteria-free control milk and incubated at 37°C to reflect physiological temperatures in the mammary gland. Levels of free fatty acids (FFA) were analyzed at time of inoculation (t=0) and after 2 and 6h of incubation, showing significant increase in FFA levels. After 2h the FFA content had increased by approximately 40% in milk samples inoculated with Staph. aureus and Strep. agalactiae, and at 6h the pathogens had increased FFA levels by 47% compared with the bacteria-free control milk. Changes in lipid composition compared with the bacteria-free control were investigated at 2 and 6h of incubation. Diacylglycerols, triacylglycerols, and phospholipids increased significantly after 6h incubation with the mastitis bacteria, whereas cholesterol and sterol esters decreased. Our results suggest that during mammary infections with Staph. aureus and Strep. agalactiae, the action of lipases originating from the mastitis pathogens will contribute significantly to milk fat lipolysis and thus to raw milk deterioration. PMID:26409975

  17. [Vaginal colonization of the Streptococcus agalactiae in pregnant woman in Tunisia: risk factors and susceptibility of isolates to antibiotics].

    PubMed

    Ferjani, A; Ben Abdallah, H; Ben Saida, N; Gozzi, C; Boukadida, J

    2006-05-01

    Streptococcus agalactiae or Group B Streptococcus (GBS) is one of the main bacterial causes of serious infections in newborns. We have evaluated prospectively GBS vaginal colonization in pregnant women and we have tried to determine the risk factors of the colonization by GBS and the particularities of the different isolated strains. We have screened 300 pregnant women with vaginal and anal sample in a same swab. Thirty nine (13%) pregnant women are colonized by SGB, 0% in the first trimester, 10.2% in the second trimester and 17% in the third trimester. Different factors are associated significantly with GBS colonization: past history of infection in newborns, genital infection during pregnancy and parity The highest rates of resistance are found in tetracycline (97.4%), erythromycin (51.3%) and lincomycin (46.2%). All the strains were susceptible to amoxicilin and pristinamycin.

  18. Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions

    SciTech Connect

    Krishnan, Vengadesan; Dwivedi, Prabhat; Kim, Brandon J.; Samal, Alexandra; Macon, Kevin; Ma, Xin; Mishra, Arunima; Doran, Kelly S.; Ton-That, Hung; Narayana, Sthanam V. L.

    2013-06-01

    The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. In addition, a homology model of the remaining two domains of GBS104 was built and a model of full-length GBS104 was generated by combining the homology model (the N1 and N4 domains) and the crystal structure of the 75 kDa fragment (the N2 and N3 domains). This rod-shaped GBS104 model is constructed of three IgG-like domains (the N1, N2 and N4 domains) and one vWFA-like domain (the N3 domain). The N1 and N2 domains of GBS104 are assembled with distinct and remote segments contributed by the N- and C-termini. The metal-binding site in the N3 domain of GBS104 is in the closed/low-affinity conformation. Interestingly, this domain hosts two long arms that project away from the metal-binding site. Using site-directed mutagenesis, two cysteine residues that lock the N3 domain of GBS104 into the open/high-affinity conformation were introduced. Both wild-type and disulfide-locked recombinant proteins were tested for binding to extracellular matrix proteins such as collagen, fibronectin, fibrinogen and laminin, and an increase in fibronectin binding affinity was identified for the disulfide-locked N3 domain, suggesting that induced conformational changes may play a possible role in receptor binding.

  19. Infection and pathology in Queensland grouper, Epinephelus lanceolatus, (Bloch), caused by exposure to Streptococcus agalactiae via different routes.

    PubMed

    Delamare-Deboutteville, J; Bowater, R; Condon, K; Reynolds, A; Fisk, A; Aviles, F; Barnes, A C

    2015-12-01

    Since 2007, 96 wild Queensland groupers, Epinephelus lanceolatus, (Bloch), have been found dead in NE Australia. In some cases, Streptococcus agalactiae (Group B Streptococcus, GBS) was isolated. At present, a GBS isolate from a wild grouper case was employed in experimental challenge trials in hatchery-reared Queensland grouper by different routes of exposure. Injection resulted in rapid development of clinical signs including bilateral exophthalmia, hyperaemic skin or fins and abnormal swimming. Death occurred in, and GBS was re-isolated from, 98% fish injected and was detected by PCR in brain, head kidney and spleen from all fish, regardless of challenge dose. Challenge by immersion resulted in lower morbidity with a clear dose response. Whilst infection was established via oral challenge by admixture with feed, no mortality occurred. Histology showed pathology consistent with GBS infection in organs examined from all injected fish, from fish challenged with medium and high doses by immersion, and from high-dose oral challenge. These experimental challenges demonstrated that GBS isolated from wild Queensland grouper reproduced disease in experimentally challenged fish and resulted in pathology that was consistent with that seen in wild Queensland grouper infected with S. agalactiae. PMID:25117665

  20. Structural Differences between the Streptococcus agalactiae Housekeeping and Pilus-Specific Sortases: SrtA and SrtC1

    SciTech Connect

    Khare, B.; Krishnan, V.; Rajashankar, K.R.; I-Hsiu, H.; Xin, M.; Ton-That, H.; Narayana, S.V.

    2011-10-21

    The assembly of pili on the cell wall of Gram-positive bacteria requires transpeptidase enzymes called sortases. In Streptococcus agalactiae, the PI-1 pilus island of strain 2603V/R encodes two pilus-specific sortases (SrtC1 and SrtC2) and three pilins (GBS80, GBS52 and GBS104). Although either pilus-specific sortase is sufficient for the polymerization of the major pilin, GBS80, incorporation of the minor pilins GBS52 and GBS104 into the pilus structure requires SrtC1 and SrtC2, respectively. The S. agalactiae housekeeping sortase, SrtA, whose gene is present at a different location and does not catalyze pilus polymerization, was shown to be involved in cell wall anchoring of pilus polymers. To understand the structural basis of sortases involved in such diverse functions, we determined the crystal structures of S. agalactiae SrtC1 and SrtA. Both enzymes are made of an eight-stranded beta-barrel core with variations in their active site architecture. SrtA exhibits a catalytic triad arrangement similar to that in Streptococcus pyogenes SrtA but different from that in Staphylococcus aureus SrtA. In contrast, the SrtC1 enzyme contains an N-terminal helical domain and a 'lid' in its putative active site, which is similar to that seen in Streptococcus pneumoniae pilus-specific sortases, although with subtle differences in positioning and composition. To understand the effect of such differences on substrate recognition, we have also determined the crystal structure of a SrtC1 mutant, in which the conserved DP(W/F/Y) motif was replaced with the sorting signal motif of GBS80, IPNTG. By comparing the structures of WT wild type SrtA and SrtC1 and the 'lid' mutant of SrtC1, we propose that structural elements within the active site and the lid may be important for defining the role of specific sortase in pili biogenesis.

  1. Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element

    PubMed Central

    2013-01-01

    Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa. PMID:24083845

  2. Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element.

    PubMed

    Fischer, Anne; Liljander, Anne; Kaspar, Heike; Muriuki, Cecilia; Fuxelius, Hans-Henrik; Bongcam-Rudloff, Erik; de Villiers, Etienne P; Huber, Charlotte A; Frey, Joachim; Daubenberger, Claudia; Bishop, Richard; Younan, Mario; Jores, Joerg

    2013-01-01

    Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa.

  3. Molecular characterization and expression of CD2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Tang, Jufen; Lu, Yishan; Jian, JiChang; Wu, Zaohe; Nie, Pin

    2016-03-01

    The cluster of differentiation 2 (CD2), functioning as a cell adhesion and costimulatory molecule, plays a crucial role in T-cell activation. In this paper, the CD2 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD2) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed On-CD2 protein consists of two extracellular Ig-like domains, a transmembrane region, and a long proline-rich cytoplasmic tail, which is a hallmark of CD2, and several important structural characteristics required for T-cell activation were detected in the deduced amino acid sequence of On-CD2. In healthy tilapia, the On-CD2 transcripts were mainly detected in the head kidney, spleen, blood and thymus. Moreover, there was a clear time-dependent expression pattern of On-CD2 after immunized by formalin-inactivated S. agalactiae and the expression reached the highest level at 12 h in the brain and head kidney, 48 h in the spleen, and 72 h in the thymus, respectively. This is the first report on the expression of CD2 induced by bacteria vaccination in teleosts. These findings indicated that On-CD2 may play an important role in the immune response to intracellular bacteria in Nile tilapia.

  4. Molecular characterization and expression of CD2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Tang, Jufen; Lu, Yishan; Jian, JiChang; Wu, Zaohe; Nie, Pin

    2016-03-01

    The cluster of differentiation 2 (CD2), functioning as a cell adhesion and costimulatory molecule, plays a crucial role in T-cell activation. In this paper, the CD2 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD2) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed On-CD2 protein consists of two extracellular Ig-like domains, a transmembrane region, and a long proline-rich cytoplasmic tail, which is a hallmark of CD2, and several important structural characteristics required for T-cell activation were detected in the deduced amino acid sequence of On-CD2. In healthy tilapia, the On-CD2 transcripts were mainly detected in the head kidney, spleen, blood and thymus. Moreover, there was a clear time-dependent expression pattern of On-CD2 after immunized by formalin-inactivated S. agalactiae and the expression reached the highest level at 12 h in the brain and head kidney, 48 h in the spleen, and 72 h in the thymus, respectively. This is the first report on the expression of CD2 induced by bacteria vaccination in teleosts. These findings indicated that On-CD2 may play an important role in the immune response to intracellular bacteria in Nile tilapia. PMID:26804651

  5. Analysis of the type II-A CRISPR-Cas system of Streptococcus agalactiae reveals distinctive features according to genetic lineages

    PubMed Central

    Lier, Clément; Baticle, Elodie; Horvath, Philippe; Haguenoer, Eve; Valentin, Anne-Sophie; Glaser, Philippe; Mereghetti, Laurent; Lanotte, Philippe

    2015-01-01

    CRISPR-Cas systems (clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins) are found in 90% of archaea and about 40% of bacteria. In this original system, CRISPR arrays comprise short, almost unique sequences called spacers that are interspersed with conserved palindromic repeats. These systems play a role in adaptive immunity and participate to fight non-self DNA such as integrative and conjugative elements, plasmids, and phages. In Streptococcus agalactiae, a bacterium implicated in colonization and infections in humans since the 1960s, two CRISPR-Cas systems have been described. A type II-A system, characterized by proteins Cas9, Cas1, Cas2, and Csn2, is ubiquitous, and a type I–C system, with the Cas8c signature protein, is present in about 20% of the isolates. Unlike type I–C, which appears to be non-functional, type II-A appears fully functional. Here we studied type II-A CRISPR-cas loci from 126 human isolates of S. agalactiae belonging to different clonal complexes that represent the diversity of the species and that have been implicated in colonization or infection. The CRISPR-cas locus was analyzed both at spacer and repeat levels. Major distinctive features were identified according to the phylogenetic lineages previously defined by multilocus sequence typing, especially for the sequence type (ST) 17, which is considered hypervirulent. Among other idiosyncrasies, ST-17 shows a significantly lower number of spacers in comparison with other lineages. This characteristic could reflect the peculiar virulence or colonization specificities of this lineage. PMID:26124774

  6. Update on control of Staphylococcus aureus and Streptococcus agalactiae for management of mastitis.

    PubMed

    Keefe, Greg

    2012-07-01

    The primary method of spread for S agalactiae and S aureus is from cow to cow, so prevention focuses on within and between herd biosecurity to reduce or eliminate the reservoir of infection. S agalactiae is an obligate pathogen of the mammary gland, whereas S aureus is more widespread on other cow body sites and in the environment. Both organisms cause persistent infections, with S agalactiae typically causing higher SCC and bacteria counts in milk. Conventional methods of detection through culture perform well at the cow level. In bulk tanks, augmented procedures should be considered. PCR methods show promise of high sensitivity and specificity, at both the cow and bulk tank level. In developed dairy industries, prevalence of infection has decreased dramatically over the past 30 years for S agalactiae. For S aureus, the herd level of infection remains very high, although with rigorous, consistent application of control measures, within-herd prevalence has decreased. Because the milking time is the primary period for new IMI, it is the focal point of most prevention activities. Premilking and postmilking teat disinfection and proper stimulation and milk-out with adequately functioning equipment are key factors. There is growing evidence that the use of milking gloves is an integral part of contagious mastitis control and the production of high-quality milk. Treatment success is dramatically different between the 2 pathogens. For S agalactiae, eradication can be completed rapidly through a culture and treatment program with minimal culling. For S aureus, treatment success, particularly during lactation, is often disappointing and depends on cow, pathogen, and treatment factors. These factors should be reviewed prior to initiating any treatment to determine the potential for cure. Blanket dry cow therapy and strategic culling are important control procedures for contagious mastitis pathogens. Maintaining a closed herd or, at minimum, adhering to clearly defined

  7. Differential diagnosis between Streptococcus agalactiae and Listeria Monocytogenes in the clinical laboratory.

    PubMed

    Kontnick, C; von Graevenitz, A; Piscitelli, V

    1977-01-01

    Streptococci of the group B (S. agalactiae) and Listeria monocytogenes resemble each other in many morphological and biochemical characteristics. Ten beta-hemolytic strains of each species were subjected to 26 tests commonly and easily performed in the clinical laboratory. Macroscopic and microscopic morphology on solid media showed differences only in the size of the colonies and in the length of the individual organisms. Among many other tests, hippurate hydrolysis and the CAMP reaction were positive in both species. In the presence of these two reaction, a negative catalase test and chaining in broth would make a presumptive diagnosis of S. agalactiae, while motility at 25 C, the presence of the Henry effect, and resistance to furadantin would be indicative of L. monocytogenes.

  8. A commercial rapid optical immunoassay detects Streptococcus agalactiae from aquatic cultures and clinical specimens.

    PubMed

    Evans, Joyce J; Pasnik, David J; Klesius, Phillip H

    2010-08-26

    The BioStar STREP B Optical ImmunoAssay (STREP B OIA) (BioStar OIA Strep B Assay Kit; BioStar Incorporation, Louisville, CO, USA), commonly used for diagnosis of human maternal group B streptococcus (GBS) colonization, was evaluated for its diagnostic and analytical sensitivity and specificity to aquatic animal GBS isolates, cross-reactivity, and diagnosis and recovery of GBS directly from clinically- infected fish swabs. STREP B OIA identified 25 known fish and dolphin GBS isolates. Thirteen non-GBS negative control isolates from fish and other animals were negative, giving 100% analytical specificity and no cross-reactivity. Three groups of 6 Nile tilapia (Oreochromis niloticus) (mean weight of 40.60+/-1.70 g) each were inoculated intraperitoneally with either 10(6) colony-forming units (cfu) GBS/fish, 10(6) cfu Streptococcus iniae/fish or 100 microL of tryptic soy broth (TSB) and observed for mortality for 7 days. The nare and brain of all fish were swabbed and subjected to the STREP B OIA for detection of GBS antigen immediately after swabbing (0 h) or 24, 48 and 72 h post-swabbing and compared to conventional culture on trypticase soy agar with 5% sheep blood. The STREP B OIA method demonstrated a diagnostic sensitivity of 75.0% and a diagnostic specificity of 69.2% compared to direct TSA. The percent agreement between OIA and culture was 100%. GBS antigen could be retrieved by OIA following 72-h storage of swabs. These results demonstrate the utility of the STREP B OIA to identify GBS from culture and directly from swabs of clinically- infected fish. PMID:20430538

  9. Evaluation of a Novel Chimeric B Cell Epitope-Based Vaccine against Mastitis Induced by Either Streptococcus agalactiae or Staphylococcus aureus in Mice▿

    PubMed Central

    Xu, Haiyang; Hu, Changmin; Gong, Rui; Chen, Yingyu; Ren, Ningning; Xiao, Ganwen; Xie, Qian; Zhang, Minmin; Liu, Qin; Guo, Aizhen; Chen, Huanchun

    2011-01-01

    To construct a universal vaccine against mastitis induced by either Streptococcus agalactiae or Staphylococcus aureus, the B cell epitopes of the surface immunogenic protein (Sip) from S. agalactiae and clumping factor A (ClfA) from S. aureus were analyzed and predicted. sip-clfA, a novel chimeric B cell epitope-based gene, was obtained by overlap PCR, and then the recombinant Sip-ClfA (rSip-ClfA) was expressed and purified. rSip-ClfA and inactivated S. agalactiae and S. aureus were formulated into different vaccines with mineral oil as the adjuvant and evaluated in mouse models. The rSip-ClfA vaccination induced immunoglobulin G (IgG) titers higher than those seen in groups immunized with inactivated bacteria. Furthermore, the response to rSip-ClfA immunization was characterized as having a dominant IgG1 subtype, whereas both bacterial immunizations produced similar levels of IgG1 and IgG2a. The antiserum capacities for opsonizing adhesion and phagocytosis were significantly greater in the rSip-ClfA immunization group than in the killed-bacterium immunization groups (P < 0.05). The immunized lactating mice were challenged with either S. agalactiae or S. aureus via the intramammary route. At 24 h postinfection, the numbers of bacteria recovered from the mammary glands in the rSip-ClfA group were >5-fold lower than those in both inactivated-bacterium groups (P < 0.01). Histopathological examination of the mammary glands showed that rSip-ClfA immunization provided better protection of mammary gland tissue integrity against both S. agalactiae and S. aureus challenges. Thus, the recombinant protein rSip-ClfA would be a promising vaccine candidate against mastitis induced by either S. agalactiae or S. aureus. PMID:21508165

  10. Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    PubMed

    Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

    2016-07-01

    PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia.

  11. Germicidal activity of a chlorous acid-chlorine dioxide teat dip and a sodium chlorite teat dip during experimental challenge with Staphylococcus aureus and Streptococcus agalactiae.

    PubMed

    Boddie, R L; Nickerson, S C; Adkinson, R W

    1998-08-01

    Three postmilking teat dips were tested for efficacy against Staphylococcus aureus and Streptococcus agalactiae in two separate studies using experimental challenge procedures that were recommended by the National Mastitis Council. The first study evaluated a barrier teat dip product containing chlorous acid-chlorine dioxide as the germicidal agent, and the second study evaluated a sodium chlorite product with a barrier component as well as a sodium chlorite product without a barrier component. The chlorous acid-chlorine dioxide teat dip reduced new intramammary infections (IMI) caused by Staph. aureus by 91.5% and reduced new IMI caused by Strep. agalactiae by 71.7%. The barrier dip containing sodium chlorite reduced new IMI caused by Staph. aureus and Strep. agalactiae by 41.0 and 0%, respectively. The nonbarrier dip containing sodium chlorite reduced new IMI caused by Staph. aureus by 65.6% and reduced new IMI caused by Strep. agalactiae by 39.1%. Teat skin and teat end conditions were evaluated before and after the second study; no deleterious effects among dipped quarters compared with control quarters were noted for the two sodium chlorite products. PMID:9749396

  12. Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    PubMed

    Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

    2016-07-01

    PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia. PMID:27033804

  13. Rga, a RofA-like regulator, is the major transcriptional activator of the PI-2a pilus in Streptococcus agalactiae.

    PubMed

    Dramsi, Shaynoor; Dubrac, Sarah; Konto-Ghiorghi, Yoan; Da Cunha, Violette; Couvé, Elisabeth; Glaser, Philippe; Caliot, Elise; Débarbouillé, Michel; Bellais, Samuel; Trieu-Cuot, Patrick; Mistou, Michel-Yves

    2012-06-01

    Rapid adaptation to changing environments is key in determining the outcome of infections caused by the opportunistic human pathogen Streptococcus agalactiae. We previously demonstrated that the RofA-like protein (RALP) regulators RogB and Rga activate their downstream divergently transcribed genes, that is, the pilus operon PI-2a and the serine-rich repeat encoding gene srr1, respectively. Characterization of the Rga regulon by microarray revealed that the PI-2a pilus was strongly controlled by Rga, a result confirmed at the protein level. Complementation experiments showed that the expression of Rga, but not RogB, in the double ΔrogB/Δrga mutant, or in the clinical strain 2603V/R displaying frameshift mutations in rogB and rga genes, is sufficient to restore wild-type expression levels of PI-2a pilus and Srr1. Biofilm formation was impaired in the Δrga and Δrga/rogB mutants and restored on complementation with rga. Paradoxically, adherence to intestinal epithelial cells was unchanged in the Δrga mutant. Finally, the existence of several clinical isolates mutated in rga highlights the concept of strain-specific regulatory networks.

  14. Genomic Diversity of Streptoccocus agalactiae Isolates from Multiple Hosts and Their Infectivity in Nile Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), has a broad host range and can be pathogenic to numerous animals, including fish. GBS is most recognized for causing cattle mastitis and human neonatal meningitis, it also causes fatal meningo-encephalitis in fish. We investigat...

  15. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus.

    PubMed

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain's cDNA is composed of 3347 bp with a 31 bp of 5'-UTR, 3015 bp open reading frame (ORF) and 301 bp 3'-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia.

  16. Detection and Enumeration of Streptococcus agalactiae from Bovine Milk Samples by Real-Time Polymerase Chain Reaction.

    PubMed

    de Carvalho, Nara Ladeira; Gonçalves, Juliano Leonel; Botaro, Bruno Garcia; Silva, Luis Felipe de Prada E; dos Santos, Marcos Veiga

    2015-09-01

    The aim of this study was to evaluate the use of real-time polymerase chain reaction (qPCR) combined with DNA extraction directly from composite milk and bulk tank samples for detection and enumeration of Streptococcus agalactiae (SAG) causing subclinical mastitis. Dilutions of sterile reconstituted skim milk inoculated with SAG ATCC 13813 were used to establish a standard curve (cfu/mL) for the qPCR assay targeting SAG. The analytical sensitivity and repeatability of the qPCR assay were determined. Bulk tank (BTM; n = 38) and composite milk samples (CM; n = 26) collected from lactating cows with positive isolation of SAG were submitted to the qPCR protocol and SAG plate counting, with results from both methods compared. Amplification of DNA was not possible in two out of 64 samples, indicating that qPCR was able to detect SAG in 96 and 97% of BTM and CM samples, respectively. The inter-assay coefficient of variation was <5%, showing that the technique had adequate repeatability. The qPCR protocol can be a high-throughput and rapid diagnostic assay to accurately detect SAG from BTM and CM samples compared with conventional microbiological culture method. However, the evaluated qPCR protocol is not accurate for enumerating SAG in milk samples, probably due to quantification of DNA of non-viable cells.

  17. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus.

    PubMed

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain's cDNA is composed of 3347 bp with a 31 bp of 5'-UTR, 3015 bp open reading frame (ORF) and 301 bp 3'-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia. PMID:27005611

  18. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus

    PubMed Central

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain’s cDNA is composed of 3347 bp with a 31 bp of 5′-UTR, 3015 bp open reading frame (ORF) and 301 bp 3′-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia. PMID:27005611

  19. Detection and Enumeration of Streptococcus agalactiae from Bovine Milk Samples by Real-Time Polymerase Chain Reaction.

    PubMed

    de Carvalho, Nara Ladeira; Gonçalves, Juliano Leonel; Botaro, Bruno Garcia; Silva, Luis Felipe de Prada E; dos Santos, Marcos Veiga

    2015-09-01

    The aim of this study was to evaluate the use of real-time polymerase chain reaction (qPCR) combined with DNA extraction directly from composite milk and bulk tank samples for detection and enumeration of Streptococcus agalactiae (SAG) causing subclinical mastitis. Dilutions of sterile reconstituted skim milk inoculated with SAG ATCC 13813 were used to establish a standard curve (cfu/mL) for the qPCR assay targeting SAG. The analytical sensitivity and repeatability of the qPCR assay were determined. Bulk tank (BTM; n = 38) and composite milk samples (CM; n = 26) collected from lactating cows with positive isolation of SAG were submitted to the qPCR protocol and SAG plate counting, with results from both methods compared. Amplification of DNA was not possible in two out of 64 samples, indicating that qPCR was able to detect SAG in 96 and 97% of BTM and CM samples, respectively. The inter-assay coefficient of variation was <5%, showing that the technique had adequate repeatability. The qPCR protocol can be a high-throughput and rapid diagnostic assay to accurately detect SAG from BTM and CM samples compared with conventional microbiological culture method. However, the evaluated qPCR protocol is not accurate for enumerating SAG in milk samples, probably due to quantification of DNA of non-viable cells. PMID:26134534

  20. Computational bacterial genome-wide analysis of phylogenetic profiles reveals potential virulence genes of Streptococcus agalactiae.

    PubMed

    Lin, Frank Po-Yen; Lan, Ruiting; Sintchenko, Vitali; Gilbert, Gwendolyn L; Kong, Fanrong; Coiera, Enrico

    2011-04-04

    The phylogenetic profile of a gene is a reflection of its evolutionary history and can be defined as the differential presence or absence of a gene in a set of reference genomes. It has been employed to facilitate the prediction of gene functions. However, the hypothesis that the application of this concept can also facilitate the discovery of bacterial virulence factors has not been fully examined. In this paper, we test this hypothesis and report a computational pipeline designed to identify previously unknown bacterial virulence genes using group B streptococcus (GBS) as an example. Phylogenetic profiles of all GBS genes across 467 bacterial reference genomes were determined by candidate-against-all BLAST searches,which were then used to identify candidate virulence genes by machine learning models. Evaluation experiments with known GBS virulence genes suggested good functional and model consistency in cross-validation analyses (areas under ROC curve, 0.80 and 0.98 respectively). Inspection of the top-10 genes in each of the 15 virulence functional groups revealed at least 15 (of 119) homologous genes implicated in virulence in other human pathogens but previously unrecognized as potential virulence genes in GBS. Among these highly-ranked genes, many encode hypothetical proteins with possible roles in GBS virulence. Thus, our approach has led to the identification of a set of genes potentially affecting the virulence potential of GBS, which are potential candidates for further in vitro and in vivo investigations. This computational pipeline can also be extended to in silico analysis of virulence determinants of other bacterial pathogens.

  1. 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

    2016-03-24

    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.

  2. Streptococcus agalactiae Meningitis in Adult Patient: A Case Report and Literature Review.

    PubMed

    Khan, Fahmi Yousef

    2016-01-01

    We report a case of group B streptococcus meningitis in a 72-year-old female patient who was admitted in our hospital with a 21-day history of bilateral lower thigh pain and swelling associated with fever, headache, and vomiting. Her past medical history was remarkable for DM type 2, hypertension, and hypothyroidism. Upon admission, examination showed bilateral warmth and tender soft tissue swelling around the knees and MRI showed cellulitis of distal thirds of both thighs. The next day, the patient became drowsy. Neurologic examination showed neck rigidity and right sided hemiparesis. Cerebrospinal fluid and blood cultures yielded group B streptococcus sensitive to ceftriaxone, penicillin G, and vancomycin. The patient received ceftriaxone for a total of 14 days after which she improved and was discharged from the hospital with right sided weakness. PMID:26904325

  3. 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

  4. Characterization of a New CAMP Factor Carried by an Integrative and Conjugative Element in Streptococcus agalactiae and Spreading in Streptococci

    PubMed Central

    Chuzeville, Sarah; Puymège, Aurore; Madec, Jean-Yves; Haenni, Marisa; Payot, Sophie

    2012-01-01

    Genetic exchanges between Streptococci occur frequently and contribute to their genome diversification. Most of sequenced streptococcal genomes carry multiple mobile genetic elements including Integrative and Conjugative Elements (ICEs) that play a major role in these horizontal gene transfers. In addition to genes involved in their mobility and regulation, ICEs also carry genes that can confer selective advantages to bacteria. Numerous elements have been described in S. agalactiae especially those integrated at the 3′ end of a tRNALys encoding gene. In strain 515 of S. agalactiae, an invasive neonate human pathogen, the ICE (called 515_tRNALys) is functional and carries different putative virulence genes including one encoding a putative new CAMP factor in addition to the one previously described. This work demonstrated the functionality of this CAMP factor (CAMP factor II) in Lactococcus lactis but also in pathogenic strains of veterinary origin. The search for co-hemolytic factors in a collection of field strains revealed their presence in S. uberis, S. dysgalactiae, but also for the first time in S. equisimilis and S. bovis. Sequencing of these genes revealed the prevalence of a species-specific factor in S. uberis strains (Uberis factor) and the presence of a CAMP factor II encoding gene in S. bovis and S. equisimilis. Furthermore, most of the CAMP factor II positive strains also carried an element integrated in the tRNALys gene. This work thus describes a CAMP factor that is carried by a mobile genetic element and has spread to different streptococcal species. PMID:23152820

  5. Short communication: comparing real-time PCR and bacteriological cultures for Streptococcus agalactiae and Staphylococcus aureus in bulk-tank milk samples.

    PubMed

    Zanardi, G; Caminiti, A; Delle Donne, G; Moroni, P; Santi, A; Galletti, G; Tamba, M; Bolzoni, G; Bertocchi, L

    2014-09-01

    For more than 30 yr, a control plan for Streptococcus agalactiae and Staphylococcus aureus has been carried out in more than 1,500 dairy herds of the province of Brescia (northern Italy). From 2010 to 2011, the apparent prevalence of Strep. agalactiae has been relatively stable around 10%, but the apparent prevalence of Staph. aureus has been greater than 40% with an increasing trend. The aim of this paper was to estimate and compare the diagnostic accuracy of 3 assays for the detection of Strep. agalactiae and Staph. aureus in bulk-tank milk samples (BTMS) in field conditions. The assays were a qualitative and a quantitative bacteriological culture (BC) for each pathogen and a homemade multiplex real-time PCR (rt-PCR). Because a gold standard was not available, the sensitivities (Se) and specificities (Sp) were evaluated using a Bayesian latent class approach. In 2012 we collected one BTMS from 165 dairy herds that were found positive for Strep. agalactiae in the previous 2-yr campaigns of eradication plan. In most cases, BTMS collected in these herds were positive for Staph. aureus as well, confirming the wide spread of this pathogen. At the same time we also collected composite milk samples from all the 8,624 lactating cows to evaluate the within-herd prevalence of Strep. agalactiae. Streptococcus agalactiae samples were cultured using a selective medium Tallium Kristalviolette Tossin, whereas for Staph. aureus, we used Baird Parker modified medium with added Rabbit Plasma Fibrinogen ISO-Formulation. In parallel, BTMS were tested using the rt-PCR. Regarding Strep. agalactiae, the posterior median of Se and Sp of the 2 BC was similar [qualitative BC: Se=98%, posterior credible interval (95%PCI): 94-100%, and Sp=99%, 95%PCI: 96-100%; quantitative BC: Se=99%, 95%PCI: 96-100%, and Sp=99%, 95%PCI: 95-100%] and higher than those of the rt-PCR (at 40 cycle threshold, Se=92%, 95%PCI: 85-97%; Sp=94%, 95%PCI: 88-98%). Also in case of Staph. aureus, the posterior medians

  6. Effect of carryover and presampling procedures on the results of real-time PCR used for diagnosis of bovine intramammary infections with Streptococcus agalactiae at routine milk recordings.

    PubMed

    Mahmmod, Yasser S; Mweu, Marshal M; Nielsen, Søren S; Katholm, Jørgen; Klaas, Ilka C

    2014-03-01

    The use of PCR tests as diagnostics for intramammary infections (IMI) based on composite milk samples collected in a non-sterile manner at milk recordings is increasing. Carryover of sample material between cows and non-aseptic PCR sampling may be incriminated for misclassification of IMI with Streptococcus agalactiae (S. agalactiae) in dairy herds with conventional milking parlours. Misclassification may result in unnecessary costs for treatment and culling. The objectives of this study were to (1) determine the effect of carryover on PCR-positivity for S. agalactiae at different PCR cycle threshold (Ct) cut-offs by estimating the between-cow correlation while accounting for the milking order, and (2) evaluate the effect of aseptic presampling procedures (PSP) on PCR-positivity at the different Ct-value cut-offs. The study was conducted in four herds with conventional milking parlours at routine milk recordings. Following the farmers' routine pre-milking preparation, 411 of 794 cows were randomly selected for the PSP treatment. These procedures included removing the first streams of milk and 70% alcohol teat disinfection. Composite milk samples were then collected from all cows and tested using PCR. Data on milking order were used to estimate the correlation between consecutively milked cows in each milking unit. Factors associated with the PCR-positivity for S. agalactiae were analyzed using generalized estimating equations assuming a binomially-distributed outcome with a logit link function. Presampling procedures were only significant using cut-off 37. A first-order autoregressive correlation structure provided the best correlation between consecutively milked cows. The correlation was 13%, 11%, 9% at cut-offs <40, 37, and 34, respectively. PSP did not reduce the odds of cows being PCR-positive for S. agalactiae. In conclusion, carryover and non-aseptic sampling affected the PCR results and should therefore be considered when samples from routine milk

  7. Streptococcus agalactiae in Brazil: serotype distribution, virulence determinants and antimicrobial susceptibility

    PubMed Central

    2014-01-01

    Background Group B Streptococcus (GBS) remains a major cause of neonatal sepsis and is also associated with invasive and noninvasive infections in pregnant women and non-pregnant adults, elderly and patients with underlying medical conditions. Ten capsular serotypes have been recognized, and determination of their distribution within a specific population or geographical region is important as they are major targets for the development of vaccine strategies. We have evaluated the characteristics of GBS isolates recovered from individuals with infections or colonization by this microorganism, living in different geographic regions of Brazil. Methods A total of 434 isolates were identified and serotyped by conventional phenotypic tests. The determination of antimicrobial susceptibility was performed by the disk diffusion method. Genes associated with resistance to erythromycin (ermA, ermB, mefA) and tetracycline (tetK, tetL, tetM, tetO) as well as virulence-associated genes (bac, bca, lmb, scpB) were investigated using PCR. Pulsed-field gel electrophoresis (PFGE) was used to examine the genetic diversity of macrolide-resistant and of a number of selected macrolide-susceptible isolates. Results Overall, serotypes Ia (27.6%), II (19.1%), Ib (18.7%) and V (13.6%) were the most predominant, followed by serotypes IV (8.1%) and III (6.7%). All the isolates were susceptible to the beta-lactam antimicrobials tested and 97% were resistant to tetracycline. Resistance to erythromycin and clindamycin were found in 4.1% and 3% of the isolates, respectively. Among the resistance genes investigated, tetM (99.3%) and tetO (1.8%) were detected among tetracycline-resistant isolates and ermA (39%) and ermB (27.6%) were found among macrolide-resistant isolates. The lmb and scpB virulence genes were detected in all isolates, while bac and bca were detected in 57 (13.1%) and 237 (54.6%) isolates, respectively. Molecular typing by PFGE showed that resistance to erythromycin was associated

  8. In vitro antimicrobial activity of Combretum molle (Combretaceae) against Staphylococcus aureus and Streptococcus agalactiae isolated from crossbred dairy cows with clinical mastitis.

    PubMed

    Regassa, Fekadu; Araya, Mengistu

    2012-08-01

    Following the rapidly expanding dairy enterprise, mastitis has remained the most economically damaging disease. The objective of this study was mainly to investigate the in vitro antibacterial activities of ethanol extracts of Combretum molle (R.Br.Ex.G.Don) Engl & Diels (Combretaceae) against antibiotic-resistant and susceptible Staphylococcus aureus and Streptococcus agalactiae isolated from clinical cases of bovine mastitis using agar disc diffusion method. The leaf and bark extracts showed antibacterial activity against S. aureus at concentrations of 3 mg/ml while the stem and seed extract did not show any bioactivity. Although both leaf and bark extracts were handled in the same manner, the antibacterial activity of the bark extract against the bacterial strains had declined gradually to a lower level as time advanced after extraction. The leaf extract had sustained bioactivity for longer duration. The susceptibility of the bacteria to the leaf extract is not obviously different between S. aureus and S. agalactiae. Also, there was no difference in susceptibility to the leaf extract between the antibiotic-resistant and antibiotic-sensitive bacteria. Further phytochemical and in vivo efficacy and safety studies are required to evaluate the therapeutic value of the plant against bovine mastitis.

  9. In vitro antimicrobial activity of Combretum molle (Combretaceae) against Staphylococcus aureus and Streptococcus agalactiae isolated from crossbred dairy cows with clinical mastitis.

    PubMed

    Regassa, Fekadu; Araya, Mengistu

    2012-08-01

    Following the rapidly expanding dairy enterprise, mastitis has remained the most economically damaging disease. The objective of this study was mainly to investigate the in vitro antibacterial activities of ethanol extracts of Combretum molle (R.Br.Ex.G.Don) Engl & Diels (Combretaceae) against antibiotic-resistant and susceptible Staphylococcus aureus and Streptococcus agalactiae isolated from clinical cases of bovine mastitis using agar disc diffusion method. The leaf and bark extracts showed antibacterial activity against S. aureus at concentrations of 3 mg/ml while the stem and seed extract did not show any bioactivity. Although both leaf and bark extracts were handled in the same manner, the antibacterial activity of the bark extract against the bacterial strains had declined gradually to a lower level as time advanced after extraction. The leaf extract had sustained bioactivity for longer duration. The susceptibility of the bacteria to the leaf extract is not obviously different between S. aureus and S. agalactiae. Also, there was no difference in susceptibility to the leaf extract between the antibiotic-resistant and antibiotic-sensitive bacteria. Further phytochemical and in vivo efficacy and safety studies are required to evaluate the therapeutic value of the plant against bovine mastitis. PMID:22207479

  10. Estimation of test characteristics of real-time PCR and bacterial culture for diagnosis of subclinical intramammary infections with Streptococcus agalactiae in Danish dairy cattle in 2012 using latent class analysis.

    PubMed

    Mahmmod, Yasser S; Toft, Nils; Katholm, Jørgen; Grønbæk, Carsten; Klaas, Ilka C

    2013-05-01

    The misdiagnosis of intramammary infections (IMI) with Streptococcus agalactiae (S. agalactiae) could lead farmers to treat or cull animals unnecessarily. The objective of this field study was to estimate the sensitivity (Se) and specificity (Sp) of real-time PCR at different cut-offs for cycle threshold (Ct) values against bacterial culture (BC) for diagnosis of S. agalactiae IMI using latent class analysis to avoid the assumption of a perfect reference test. A total of 614 dairy cows were randomly selected from 6 herds with bulk tank PCR Ct value ≤ 39 for S. agalactiae and S. aureus. At milk recording, 2456 quarter milk samples were taken aseptically for BC and the routinely taken cow level milk samples were analyzed by PCR. Results showed that 53 cows (8.6%) were positive for S. agalactiae IMI by BC. Sensitivity of PCR at cut-offs; ≤ 39, ≤ 37, ≤ 34, and ≤ 32, was 96.2%, 91.9%, 87.2% and 73.9%, while Se of BC was 25.7%, 29.9%, 59.9% and 72.1%. Specificity of PCR at cut-offs; ≤ 39, ≤ 37, ≤ 34, and ≤ 32, was 96.8%, 96.9%, 96.7%, and 97.22%, while Sp of BC was 99.7%, 99.5%, 99.2%, and 98.9%. The estimated prevalence of S. agalactiae IMI by PCR was higher than the apparent prevalence at the tested cut-offs, indicating under estimation of S. agalactiae IMI in the examined dairy cows. In conclusion, Se of PCR is always higher than Se of BC at all tested cut-offs. The lower cut-off, the more comparable becomes Se of PCR and Se of BC. The changes in Se in both PCR and BC at different Ct-value cut-offs may indicate a change in the definition of the latent infection. The similar Se of both tests at cut-off ≤ 32 may indicate high concentrations of S. agalactiae viable cells, representing a cow truly/heavily infected with S. agalactiae and thus easier to detect with BC. At cut-off ≤ 39 the latent definition of infection may reflect a more general condition of cows being positive for S. agalactiae. Our findings indicate that PCR Ct-value cut-offs should

  11. Novel aspects of the Z and R3 antigens of Streptococcus agalactiae revealed by immunological testing.

    PubMed

    Maeland, Johan A; Radtke, Andreas; Lyng, Randi V; Mavenyengwa, Rooyen T

    2013-04-01

    Group B streptococci (GBS) are important human and bovine pathogens which can be classified by a variety of phenotype- and gene-based techniques. The capsular polysaccharide and strain-variable, surface-anchored proteins are particularly important phenotypic markers. In an earlier study, a previously unrecognized protein antigen called Z was described. It was expressed by 27.2% of GBS strains from Zimbabwe, usually in combination with R3 protein expression. In this study, a putative Z-specific antiserum actually contained antibodies against two different antigens named Z1 and Z2; Z1 was >250 kDa in molecular mass. Z1, Z2, and R3 generated multiple stained bands on Western blots and showed similar chromatographic characteristics with respect to molecular mass, aggregate formation, and charge. Of 28 reference and prototype GBS strains examined, 8/28 (28.5%) isolates expressed one, two, or all three of the Z1, Z2, and R3 antigens; 4/28 expressed all three antigens; 2/28 expressed Z2 and R3; 1/28 expressed Z1 only; and 1/28 expressed R3 only. Twenty (71.5%) of the 28 isolates expressed none of the three antigens. Expression of one or more of these antigens was shown by isolates of the capsular polysaccharide types Ia, Ib, V, and IX and NT strains and occurred in combination with expression of various other strain-variable and surface-localized protein antigens. When used as serosubtype markers, Z1, Z2, and R3 affected existing GBS serotype designations for some of the isolates. For instance, the R3 reference strain Prague 10/84 (ATCC 49447) changed serotype markers from V/R3 to V/R3, Z1, and Z2. Other isolates may change correspondingly, implying consequences for GBS serotyping and research. PMID:23408530

  12. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages

    PubMed Central

    Campisi, Edmondo; Rinaudo, C. Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S.; Baker, Carol J.; Margarit, Imma; Rosini, Roberto

    2016-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV. PMID:27411639

  13. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages.

    PubMed

    Campisi, Edmondo; Rinaudo, C Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S; Baker, Carol J; Margarit, Imma; Rosini, Roberto

    2016-07-14

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV.

  14. Serotype IV Streptococcus agalactiae ST-452 has arisen from large genomic recombination events between CC23 and the hypervirulent CC17 lineages.

    PubMed

    Campisi, Edmondo; Rinaudo, C Daniela; Donati, Claudio; Barucco, Mara; Torricelli, Giulia; Edwards, Morven S; Baker, Carol J; Margarit, Imma; Rosini, Roberto

    2016-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) causes life-threatening infections in newborns and adults with chronic medical conditions. Serotype IV strains are emerging both among carriers and as cause of invasive disease and recent studies revealed two main Sequence Types (STs), ST-452 and ST-459 assigned to Clonal Complexes CC23 and CC1, respectively. Whole genome sequencing of 70 type IV GBS and subsequent phylogenetic analysis elucidated the localization of type IV isolates in a SNP-based phylogenetic tree and suggested that ST-452 could have originated through genetic recombination. SNPs density analysis of the core genome confirmed that the founder strain of this lineage originated from a single large horizontal gene transfer event between CC23 and the hypervirulent CC17. Indeed, ST-452 genomes are composed by two parts that are nearly identical to corresponding regions in ST-24 (CC23) and ST-291 (CC17). Chromosome mapping of the major GBS virulence factors showed that ST-452 strains have an intermediate yet unique profile among CC23 and CC17 strains. We described unreported large recombination events, involving the cps IV operon and resulting in the expansion of serotype IV to CC23. This work sheds further light on the evolution of GBS providing new insights on the recent emergence of serotype IV. PMID:27411639

  15. Comprehensive identification and profiling of Nile tilapia (Oreochromis niloticus) microRNAs response to Streptococcus agalactiae infection through high-throughput sequencing.

    PubMed

    Wang, Bei; Gan, Zhen; Cai, Shuanghu; Wang, Zhongliang; Yu, Dapeng; Lin, Ziwei; Lu, Yishan; Wu, Zaohe; Jian, Jichang

    2016-07-01

    MicroRNAs are a kind of small non-coding RNAs that participate in various biological processes. Deregulated microRNA expression is associated with several types of diseases. Tilapia (Oreochromis niloticus) is an important commercial fish species in China. To identify miRNAs and investigate immune-related miRNAs of O. niloticus, we applied high-throughput sequencing technology to identify and analyze miRNAs from tilapia infected with Streptococcus agalactiae at a timescale of 72 h divided into six different time points. The results showed that a total of 3009 tilapia miRNAs were identified, including in 1121 miRNAs which have homologues in the currently available databases and 1878 novel miRNAs. The expression levels of 218 tilapia miRNAs were significantly altered at 6 h-72 h post-bacterial infection (pi), and these miRNAs were therefore classified as differentially expressed tilapia miRNAs. For the 1121 differentially expressed tilapia miRNAs target 41961 genes. GO and KEGG enrichment analysis revealed that some target genes of tilapia miRNAs were grouped mainly into the categories of apoptotic process, signal pathway, and immune response. This is the first report of comprehensive identification of O. niloticus miRNAs being differentially regulated in spleen in normal conditions relating to S. agalactiae infection. This work provides an opportunity for further understanding of the molecular mechanisms of miRNA regulation in O. niloticus host-pathogen interactions.

  16. Comprehensive identification and profiling of Nile tilapia (Oreochromis niloticus) microRNAs response to Streptococcus agalactiae infection through high-throughput sequencing.

    PubMed

    Wang, Bei; Gan, Zhen; Cai, Shuanghu; Wang, Zhongliang; Yu, Dapeng; Lin, Ziwei; Lu, Yishan; Wu, Zaohe; Jian, Jichang

    2016-07-01

    MicroRNAs are a kind of small non-coding RNAs that participate in various biological processes. Deregulated microRNA expression is associated with several types of diseases. Tilapia (Oreochromis niloticus) is an important commercial fish species in China. To identify miRNAs and investigate immune-related miRNAs of O. niloticus, we applied high-throughput sequencing technology to identify and analyze miRNAs from tilapia infected with Streptococcus agalactiae at a timescale of 72 h divided into six different time points. The results showed that a total of 3009 tilapia miRNAs were identified, including in 1121 miRNAs which have homologues in the currently available databases and 1878 novel miRNAs. The expression levels of 218 tilapia miRNAs were significantly altered at 6 h-72 h post-bacterial infection (pi), and these miRNAs were therefore classified as differentially expressed tilapia miRNAs. For the 1121 differentially expressed tilapia miRNAs target 41961 genes. GO and KEGG enrichment analysis revealed that some target genes of tilapia miRNAs were grouped mainly into the categories of apoptotic process, signal pathway, and immune response. This is the first report of comprehensive identification of O. niloticus miRNAs being differentially regulated in spleen in normal conditions relating to S. agalactiae infection. This work provides an opportunity for further understanding of the molecular mechanisms of miRNA regulation in O. niloticus host-pathogen interactions. PMID:27050313

  17. Effects of some dietary crude plant extracts on the growth and gonadal maturity of Nile tilapia (Oreochromis niloticus) and their resistance to Streptococcus agalactiae infection.

    PubMed

    Kareem, Zana H; Abdelhadi, Yasser M; Christianus, Annie; Karim, Murni; Romano, Nicholas

    2016-04-01

    A 90-day feeding trial was conducted on the growth performance, feeding efficacy, body indices, various hematological and plasma biochemical parameters, and histopathological examination of the gonads from male and female Nile tilapia fingerlings when fed different crude plant extracts from Cinnamomum camphora, Euphorbia hirta, Azadirachta indica, or Carica papaya at 2 g kg(-1) compared to a control diet. This was followed by a 14-day challenge to Streptococcus agalactiae. All treatments were triplicated, and each treatment consisted of 30 fish. Results showed that C. papaya extracts were the most effective at delaying gonadal maturation to both male and female tilapia, as well as significantly increasing (P < 0.05) growth performance compared to the control treatment. Similarly, dietary C. camphora and E. hirta extracts also significantly improved growth, while no significant growth effect was detected between the A. indica and control treatments (P > 0.05). Further, crude body lipid was lower in the C. camphora, E. hirta and C. papaya treatments, but was only significantly lower for the E. hirta treatment compared to the control. Meanwhile, none of the hematological or biochemical parameters were significantly affected, although plasma ALT was significantly lower for tilapia fed A. indica compared to the control. After the 14-day bacterial challenge, tilapia fed C. camphora supplementation had significantly higher survival, compared to the control, but was not significantly higher than the other supplemented diets. Results indicate that dietary C. papaya extract can significantly promote growth and delay gonadal maturation to both male and female tilapia, while C. camphora was the most effective prophylactic to S. agalactiae and may be a cost-effective and eco-friendly alternative to antibiotics. PMID:26643907

  18. Molecular epidemiology and distribution of serotypes, genotypes, and antibiotic resistance genes of Streptococcus agalactiae clinical isolates from Guelma, Algeria and Marseille, France.

    PubMed

    Bergal, A; Loucif, L; Benouareth, D E; Bentorki, A A; Abat, C; Rolain, J-M

    2015-12-01

    This study describes, for the first time, the genetic and phenotypic diversity among 93 Streptococcus agalactiae (group B Streptococcus, GBS) isolates collected from Guelma, Algeria and Marseille, France. All strains were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The molecular support of antibiotic resistance and serotyping were investigated by polymerase chain reaction (PCR). The phylogenetic lineage of each GBS isolate was determined by multilocus sequence typing (MLST) and grouped into clonal complexes (CCs) using eBURST. The isolates represented 37 sequence types (STs), 16 of which were novel, grouped into five CCs, and belonging to seven serotypes. Serotype V was the most prevalent serotype in our collection (44.1%). GBS isolates of each serotype were distributed among multiple CCs, including cps III/CC19, cps V/CC1, cps Ia/CC23, cps II/CC10, and cps III/CC17. All isolates presented susceptibility to penicillin, whereas resistance to erythromycin was detected in 40% and tetracycline in 82.2% of isolates. Of the 37 erythromycin-resistant isolates, 75.7% showed the macrolide-lincosamide-streptogramin B (MLSB)-resistant phenotype and 24.3% exhibited the macrolide (M)-resistant phenotype. Constitutive MLSB resistance (46%) mediated by the ermB gene was significantly associated with the Guelma isolates, whereas the M resistance phenotype (24.3%) mediated by the mefA/E gene dominated among the Marseille isolates and belonged to ST-23. Tetracycline resistance was predominantly due to tetM, which was detected alone (95.1%) or associated with tetO (3.7%). These results provide epidemiological data in these regions that establish a basis for monitoring increased resistance to erythromycin and also provide insight into correlations among clones, serotypes, and resistance genes.

  19. RNA-Seq revealed the impairment of immune defence of tilapia against the infection of Streptococcus agalactiae with simulated climate warming.

    PubMed

    Wang, Le; Liu, Peng; Wan, Zi Yi; Huang, Shu Qing; Wen, Yan Fei; Lin, Grace; Yue, Gen Hua

    2016-08-01

    Global warming is one of the causes of disease outbreaks in fishes. Understanding its mechanisms is critical in aquaculture and fisheries. We used tilapia to study the effects of a high temperature on the infection of a bacterial pathogen Streptococcus agalactiae using RNA-Seq. We found that the dissolved oxygen level in water at 32 °C is lower than at 22 °C, and tilapia infected with the pathogen died more rapidly at 32 °C. The gene expression profiles showed significant differences in fish raised under different conditions. We identified 126 and 576 differentially expressed genes (DEGs) at 4 and 24 h post infection at 22 °C, respectively, whereas at 32 °C, the data were 312 and 1670, respectively. Almost all responding pathways at 22 °C were involved in the immune responses, whereas at 32 °C, the enriched pathways were not only involved in immune responses but also involved in oxygen and energy metabolisms. We identified significant signals of immunosuppression of immune responses at 32 °C. In addition, many of the enriched transcription factors and DEGs under positive selection were involved in immune responses, oxygen and/or energy metabolisms. Our results suggest that global warming could reduce the oxygen level in water and impair the defence of tilapia against bacterial infection. PMID:27377027

  20. An in silico model for identification of small RNAs in whole bacterial genomes: characterization of antisense RNAs in pathogenic Escherichia coli and Streptococcus agalactiae strains

    PubMed Central

    Pichon, Christophe; du Merle, Laurence; Caliot, Marie Elise; Trieu-Cuot, Patrick; Le Bouguénec, Chantal

    2012-01-01

    Characterization of small non-coding ribonucleic acids (sRNA) among the large volume of data generated by high-throughput RNA-seq or tiling microarray analyses remains a challenge. Thus, there is still a need for accurate in silico prediction methods to identify sRNAs within a given bacterial species. After years of effort, dedicated software were developed based on comparative genomic analyses or mathematical/statistical models. Although these genomic analyses enabled sRNAs in intergenic regions to be efficiently identified, they all failed to predict antisense sRNA genes (asRNA), i.e. RNA genes located on the DNA strand complementary to that which encodes the protein. The statistical models enabled any genomic region to be analyzed theorically but not efficiently. We present a new model for in silico identification of sRNA and asRNA candidates within an entire bacterial genome. This model was successfully used to analyze the Gram-negative Escherichia coli and Gram-positive Streptococcus agalactiae. In both bacteria, numerous asRNAs are transcribed from the complementary strand of genes located in pathogenicity islands, strongly suggesting that these asRNAs are regulators of the virulence expression. In particular, we characterized an asRNA that acted as an enhancer-like regulator of the type 1 fimbriae production involved in the virulence of extra-intestinal pathogenic E. coli. PMID:22139924

  1. An in silico model for identification of small RNAs in whole bacterial genomes: characterization of antisense RNAs in pathogenic Escherichia coli and Streptococcus agalactiae strains.

    PubMed

    Pichon, Christophe; du Merle, Laurence; Caliot, Marie Elise; Trieu-Cuot, Patrick; Le Bouguénec, Chantal

    2012-04-01

    Characterization of small non-coding ribonucleic acids (sRNA) among the large volume of data generated by high-throughput RNA-seq or tiling microarray analyses remains a challenge. Thus, there is still a need for accurate in silico prediction methods to identify sRNAs within a given bacterial species. After years of effort, dedicated software were developed based on comparative genomic analyses or mathematical/statistical models. Although these genomic analyses enabled sRNAs in intergenic regions to be efficiently identified, they all failed to predict antisense sRNA genes (asRNA), i.e. RNA genes located on the DNA strand complementary to that which encodes the protein. The statistical models enabled any genomic region to be analyzed theorically but not efficiently. We present a new model for in silico identification of sRNA and asRNA candidates within an entire bacterial genome. This model was successfully used to analyze the Gram-negative Escherichia coli and Gram-positive Streptococcus agalactiae. In both bacteria, numerous asRNAs are transcribed from the complementary strand of genes located in pathogenicity islands, strongly suggesting that these asRNAs are regulators of the virulence expression. In particular, we characterized an asRNA that acted as an enhancer-like regulator of the type 1 fimbriae production involved in the virulence of extra-intestinal pathogenic E. coli.

  2. RNA-Seq revealed the impairment of immune defence of tilapia against the infection of Streptococcus agalactiae with simulated climate warming.

    PubMed

    Wang, Le; Liu, Peng; Wan, Zi Yi; Huang, Shu Qing; Wen, Yan Fei; Lin, Grace; Yue, Gen Hua

    2016-08-01

    Global warming is one of the causes of disease outbreaks in fishes. Understanding its mechanisms is critical in aquaculture and fisheries. We used tilapia to study the effects of a high temperature on the infection of a bacterial pathogen Streptococcus agalactiae using RNA-Seq. We found that the dissolved oxygen level in water at 32 °C is lower than at 22 °C, and tilapia infected with the pathogen died more rapidly at 32 °C. The gene expression profiles showed significant differences in fish raised under different conditions. We identified 126 and 576 differentially expressed genes (DEGs) at 4 and 24 h post infection at 22 °C, respectively, whereas at 32 °C, the data were 312 and 1670, respectively. Almost all responding pathways at 22 °C were involved in the immune responses, whereas at 32 °C, the enriched pathways were not only involved in immune responses but also involved in oxygen and energy metabolisms. We identified significant signals of immunosuppression of immune responses at 32 °C. In addition, many of the enriched transcription factors and DEGs under positive selection were involved in immune responses, oxygen and/or energy metabolisms. Our results suggest that global warming could reduce the oxygen level in water and impair the defence of tilapia against bacterial infection.

  3. Evaluation of the brain-derived neurotrophic factor, nerve growth factor and memory in adult rats survivors of the neonatal meningitis by Streptococcus agalactiae.

    PubMed

    Barichello, Tatiana; Lemos, Joelson C; Generoso, Jaqueline S; Carradore, Mirelle M; Moreira, Ana Paula; Collodel, Allan; Zanatta, Jessiele R; Valvassori, Samira S; Quevedo, João

    2013-03-01

    Streptococcus agalactiae (GBS) is a major cause of severe morbidity and mortality in neonates and young infants, causing sepsis, pneumonia and meningitis. The survivors from this meningitis can suffer serious long-term neurological consequences, such as, seizures, hearing loss, learning and memory impairments. Neurotrophins, such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) control the neuronal cell death during the brain development and play an important role in neuronal differentiation, survival and growth of neurons. Neonate Wistar rats, received either 10μL of sterile saline as a placebo or an equivalent volume of GBS suspension at a concentration of 1×10(6)cfu/mL. Sixty days after induction of meningitis, the animals underwent behavioral tests, after were killed and the hippocampus and cortex were retired for analyze of the BDNF and NGF levels. In the open-field demonstrated no difference in motor, exploratory activity and habituation memory between the groups. The step-down inhibitory avoidance, when we evaluated the long-term memory at 24h after training session, we found that the meningitis group had a decrease in aversive memory when compared with the long-term memory test of the sham group. BDNF levels decreased in hippocampus and cortex; however the NGF levels decreased only in hippocampus. These findings suggest that the meningitis model could be a good research tool for the study of the biological mechanisms involved in the behavioral alterations secondary to GBS meningitis.

  4. Clinicopathological features and immunohistochemical detection of antigens in acute experimental Streptococcus agalactiae infection in red tilapia (Oreochromis spp.).

    PubMed

    Abdullah, Syuhaidah; Omar, Noraini; Yusoff, Sabri Mohd; Obukwho, Emikpe Benjamin; Nwunuji, Tanko Polycarp; Hanan, Latifah; Samad, Jamil

    2013-01-01

    This study investigates the clinicopathological features of acute experimental streptococcosis in red tilapia using various routes of infection; intraperitoneal (IP), immersion (IM) and immersion cut (IC). Twenty four red tilapia in duplicates were inoculated intraperitoneally with 10(9) CFU/ml of S. agalactiae while another sets: intact, one with sharp cut at the tail end were exposed to bacterial inoculums 10(9) CFU/ml diluted in water while two groups of control fish were similarly manipulated. Clinical signs were recorded; samples from the gills, brain, eyes and kidneys were also taken for bacterial isolation and histopathology. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) were employed to detect the antigen. The diseased fish showed skin, fin haemorrhages and exophthalmia with obvious signs in IP at 2 hpc followed by IC and IM at 4 hpc. The lesions were noticed earlier in the kidney and most severe in IP. IHC detected antigen as early as PCR and isolation with intense staining in blood vessel lumen and wall, macrophages in choroid, focal haemorrhage in the renal interstitium and meninges especially in IP followed by IC and IM. The immunolocalisation of the antigen described for the first time further explain the pathogenesis of streptococcosis in red tilapia. PMID:23961386

  5. O-Glycosylation of the N-terminal Region of the Serine-rich Adhesin Srr1 of Streptococcus agalactiae Explored by Mass Spectrometry *

    PubMed Central

    Chaze, Thibault; Guillot, Alain; Valot, Benoît; Langella, Olivier; Chamot-Rooke, Julia; Di Guilmi, Anne-Marie; Trieu-Cuot, Patrick; Dramsi, Shaynoor; Mistou, Michel-Yves

    2014-01-01

    Serine-rich (Srr) proteins exposed at the surface of Gram-positive bacteria are a family of adhesins that contribute to the virulence of pathogenic staphylococci and streptococci. Lectin-binding experiments have previously shown that Srr proteins are heavily glycosylated. We report here the first mass-spectrometry analysis of the glycosylation of Streptococcus agalactiae Srr1. After Srr1 enrichment and trypsin digestion, potential glycopeptides were identified in collision induced dissociation spectra using X! Tandem. The approach was then refined using higher energy collisional dissociation fragmentation which led to the simultaneous loss of sugar residues, production of diagnostic oxonium ions and backbone fragmentation for glycopeptides. This feature was exploited in a new open source software tool (SpectrumFinder) developed for this work. By combining these approaches, 27 glycopeptides corresponding to six different segments of the N-terminal region of Srr1 [93–639] were identified. Our data unambiguously indicate that the same protein residue can be modified with different glycan combinations including N-acetylhexosamine, hexose, and a novel modification that was identified as O-acetylated-N-acetylhexosamine. Lectin binding and monosaccharide composition analysis strongly suggested that HexNAc and Hex correspond to N-acetylglucosamine and glucose, respectively. The same protein segment can be modified with a variety of glycans generating a wide structural diversity of Srr1. Electron transfer dissociation was used to assign glycosylation sites leading to the unambiguous identification of six serines and one threonine residues. Analysis of purified Srr1 produced in mutant strains lacking accessory glycosyltransferase encoding genes demonstrates that O-GlcNAcylation is an initial step in Srr1 glycosylation that is likely required for subsequent decoration with Hex. In summary, our data obtained by a combination of fragmentation mass spectrometry techniques

  6. Phenotypic and genotypic characterization of Streptococcus agalactiae in pregnant women. First study in a province of Argentina

    PubMed Central

    Oviedo, P; Pegels, E; Laczeski, M; Quiroga, M; Vergara, M

    2013-01-01

    Group B Streptococcus (GBS) is the leading cause of neonatal infections. Our purpose was to characterize GBS colonization in pregnant women, current serotypes, resistance phenotypes and genes associated with virulence. In Misiones, Argentina, there are no previous data on this topic. Vaginal-rectal swabs from 3125 pregnant women were studied between 2004 and 2010. GBS strains were identified by conventional and serological methods (Phadebact Strep B Test, ETC International, Bactus AB, Sweden). Serotypes were detected using Strep-B Latex (Statens Serum Institut, Denmark). Resistance phenotypes were determined by the double-disk test. Genes were studied by PCR. Maternal colonization was 9.38%. Resistance to erythromycin was 11.6%, and the constitutive phenotype was the predominant one. Serotype Ia was the most frequent, whereas serotypes IV, VI, VII and VIII were not detected. The lmb, bca and hylB genes were detected in more than 79% of the strains. In this study, the colonization rate with GBS and the serotype distribution were compared with studies reported in other areas of the country. The high resistance to erythromycin in Misiones justifies performing antibiotic susceptibility testing. The serotype distribution, the genes encoding putative virulence factors, and the patterns of resistance phenotypes of GBS may vary in different areas. They thus need to be evaluated in each place to devise strategies for prevention. PMID:24159312

  7. Characterization of Isolates of Streptococcus agalactiae from Diseased Farmed and Wild Marine Fish from the U.S. Gulf Coast, Latin America, and Thailand.

    PubMed

    Soto, Esteban; Wang, Rui; Wiles, Judy; Baumgartner, Wes; Green, Christopher; Plumb, John; Hawke, John

    2015-06-01

    We examined Lancefield serogroup B Streptococcus isolates recovered from diseased, cultured hybrid Striped Bass (Striped Bass Morone saxatilis × White Bass M. chrysops) and wild and cultured Gulf Killifish Fundulus grandis from coastal waters of the U.S. Gulf of Mexico (Gulf coast) and compared those isolates to strains from tilapias Oreochromis spp. reared in Mississippi, Thailand, Ecuador, and Honduras and to the original Gulf coast strain identified by Plumb et al. ( 1974 ). The isolates were subjected to phylogenetic, biochemical, and antibiotic susceptibility analyses. Genetic analysis was performed using partial sequence comparison of (1) the 16S ribosomal RNA (rRNA) gene; (2) the sipA gene, which encodes a surface immunogenic protein; (3) the cspA gene, which encodes a cell surface-associated protein; and (4) the secY gene, which encodes components of a general protein secretion pathway. Phylogenies inferred from sipA, secY, and cspA gene sequence comparisons were more discriminating than that inferred from the 16S rRNA gene sequence comparison. The U.S. Gulf coast strains showed a high degree of similarity to strains from South America and Central America and belonged to a unique group that can be distinguished from other group B streptococci. In agreement with the molecular findings, biochemical and antimicrobial resistance analyses demonstrated that the isolates recovered from the U.S. Gulf coast and Latin America were more similar to each other than to isolates from Thailand. Three laboratory challenge methods for inducing streptococcosis in Gulf Killifish were evaluated-intraperitoneal (IP) injection, immersion (IMM), and immersion plus abrasion (IMMA)-using serial dilutions of S. agalactiae isolate LADL 97-151, a representative U.S. Gulf coast strain. The dose that was lethal to 50% of test fish by 14 d postchallenge was approximately 2 CFU/fish via IP injection. In contrast, the fish that were challenged via IMM or IMMA presented cumulative mortality

  8. Characterization of Isolates of Streptococcus agalactiae from Diseased Farmed and Wild Marine Fish from the U.S. Gulf Coast, Latin America, and Thailand.

    PubMed

    Soto, Esteban; Wang, Rui; Wiles, Judy; Baumgartner, Wes; Green, Christopher; Plumb, John; Hawke, John

    2015-06-01

    We examined Lancefield serogroup B Streptococcus isolates recovered from diseased, cultured hybrid Striped Bass (Striped Bass Morone saxatilis × White Bass M. chrysops) and wild and cultured Gulf Killifish Fundulus grandis from coastal waters of the U.S. Gulf of Mexico (Gulf coast) and compared those isolates to strains from tilapias Oreochromis spp. reared in Mississippi, Thailand, Ecuador, and Honduras and to the original Gulf coast strain identified by Plumb et al. ( 1974 ). The isolates were subjected to phylogenetic, biochemical, and antibiotic susceptibility analyses. Genetic analysis was performed using partial sequence comparison of (1) the 16S ribosomal RNA (rRNA) gene; (2) the sipA gene, which encodes a surface immunogenic protein; (3) the cspA gene, which encodes a cell surface-associated protein; and (4) the secY gene, which encodes components of a general protein secretion pathway. Phylogenies inferred from sipA, secY, and cspA gene sequence comparisons were more discriminating than that inferred from the 16S rRNA gene sequence comparison. The U.S. Gulf coast strains showed a high degree of similarity to strains from South America and Central America and belonged to a unique group that can be distinguished from other group B streptococci. In agreement with the molecular findings, biochemical and antimicrobial resistance analyses demonstrated that the isolates recovered from the U.S. Gulf coast and Latin America were more similar to each other than to isolates from Thailand. Three laboratory challenge methods for inducing streptococcosis in Gulf Killifish were evaluated-intraperitoneal (IP) injection, immersion (IMM), and immersion plus abrasion (IMMA)-using serial dilutions of S. agalactiae isolate LADL 97-151, a representative U.S. Gulf coast strain. The dose that was lethal to 50% of test fish by 14 d postchallenge was approximately 2 CFU/fish via IP injection. In contrast, the fish that were challenged via IMM or IMMA presented cumulative mortality

  9. Diversity of human small intestinal Streptococcus and Veillonella populations.

    PubMed

    van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

    2013-08-01

    Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed abundant populations of Streptococcus spp. most affiliated with S. salivarius, S. thermophilus, and S. parasanguinis, as well as Veillonella spp. affiliated with V. atypica, V. parvula, V. dispar, and V. rogosae. Relative abundances varied per subject and time of sampling. Streptococcus and Veillonella isolates were cultured using selective media from ileostoma effluent samples collected at two time points from a single subject. The richness of the Streptococcus and Veillonella isolates was assessed at species and strain level by 16S rRNA gene sequencing and genetic fingerprinting, respectively. A total of 160 Streptococcus and 37 Veillonella isolates were obtained. Genetic fingerprinting differentiated seven Streptococcus lineages from ileostoma effluent, illustrating the strain richness within this ecosystem. The Veillonella isolates were represented by a single phylotype. Our study demonstrated that the small intestinal Streptococcus populations displayed considerable changes over time at the genetic lineage level because only representative strains of a single Streptococcus lineage could be cultivated from ileostoma effluent at both time points.

  10. CsrRS and Environmental pH Regulate Group B Streptococcus Adherence to Human Epithelial Cells and Extracellular Matrix

    PubMed Central

    Park, Su Eun; Jiang, Shengmei

    2012-01-01

    Streptococcus agalactiae (group B Streptococcus or GBS) is a common colonizer of the gastrointestinal and genital tracts and an important cause of invasive infections in newborn infants and in adults with predisposing chronic conditions or advanced age. Attachment to epithelial surfaces at mucosal sites is a critical step in the successful colonization of a human host, and regulation of this process is likely to play an important role in both commensalism and dissemination to cause invasive disease. We found that inactivation of the CsrRS (or CovRS) two-component system increased GBS adherence to epithelial cells derived from human vaginal, cervical, and respiratory epithelium, as well as increasing adherence to extracellular matrix proteins and increasing biofilm formation on polystyrene. Neutral (as opposed to acidic) pH enhanced GBS binding to vaginal epithelial cells and to fibrinogen and fibronectin, effects that were partially dependent on CsrRS. The regulatory effects of CsrRS and environmental pH on bacterial adherence correlated with their effects on the expression of multiple surface adhesins, as assessed by quantitative reverse transcription-PCR. We conclude that GBS adherence to epithelial and abiotic surfaces is regulated by the CsrRS two-component system and by environmental pH through their regulatory effects on the expression of bacterial surface adhesins. Dynamic regulation of GBS adherence enhances the organism's adaptability to survival in multiple niches in the human host. PMID:22949550

  11. Streptococcus rubneri sp. nov., isolated from the human throat.

    PubMed

    Huch, Melanie; De Bruyne, Katrien; Cleenwerck, Ilse; Bub, Achim; Cho, Gyu-Sung; Watzl, Bernhard; Snauwaert, Isabel; Franz, Charles M A P; Vandamme, Peter

    2013-11-01

    The novel, Gram-stain-positive, ovoid, lactic acid bacterial isolates LMG 27205, LMG 27206, LMG 27207(T) and MRI-F 18 were obtained from throat samples of healthy humans. 16S rRNA gene sequence analyses indicated that these isolates belong to the genus Streptococcus, specifically the Streptococcus mitis group, with Streptococcus australis and Streptococcus mitis as the nearest neighbours (99.45 and 98.56 % 16S rRNA gene sequence similarity to the respective type strains). Genotypic fingerprinting by fluorescent amplified fragment length polymorphism (FAFLP) and pulsed-field gel electrophoresis (PFGE), DNA-DNA hybridizations, comparative sequence analysis of pheS, rpoA and atpA and physiological and biochemical tests revealed that these bacteria formed a taxon well separated from its nearest neighbours and other species of the genus Streptococcus with validly published names and, therefore, represent a novel species, for which the name Streptococcus rubneri sp. nov. is proposed, with LMG 27207(T) ( = DSM 26920(T)) as the type strain.

  12. Evaluation of methods for identification and determination of the taxonomic status of strains belonging to the Streptococcus porcinus-Streptococcus pseudoporcinus complex isolated from animal, human, and dairy sources.

    PubMed

    Shewmaker, Patricia Lynn; Steigerwalt, Arnold G; Whitney, Anne M; Morey, Roger E; Graziano, James C; Facklam, Richard R; Musser, Kimberlee A; Merquior, Vânia L C; Teixeira, Lucia M

    2012-11-01

    Ninety-seven animal, human, and dairy Streptococcus porcinus or Streptococcus pseudoporcinus isolates in the CDC Streptococcus strain collection were evaluated on the basis of DNA-DNA reassociation, 16S rRNA and rpoB gene sequencing, conventional biochemical and Rapid ID 32 Strep identification methods, and antimicrobial susceptibility testing to determine their taxonomic status, characteristics for species differentiation, antimicrobial susceptibility, and relevance of clinical source. Nineteen of the 97 isolates (1 human, 18 swine) were identified as S. porcinus. The remaining 72 human isolates and 6 dairy isolates were identified as S. pseudoporcinus. The use of 16S rRNA or rpoB gene sequencing was required to differentiate S. porcinus from S. pseudoporcinus. The human and dairy S. pseudoporcinus isolates were biochemically distinct from each other as well as distinct by 16S rRNA and rpoB gene sequencing. Therefore, we propose the subspecies denominations S. pseudoporcinus subsp. hominis subsp. nov. for the human isolates and S. pseudoporcinus subsp. lactis subsp. nov. for the dairy isolates. Most strains were susceptible to the antimicrobials tested, with the exception of tetracycline. Two strains of each species were also resistant to clindamycin and erythromycin and carried the erm(A) (S. pseudoporcinus) or the erm(B) (S. porcinus) gene. S. porcinus was identified from a single human isolate recovered from a wound in an abattoir worker. S. pseudoporcinus was primarily isolated from the genitourinary tract of women but was also associated with blood, placental, and wound infections. Isolates reacting with group B antiserum and demonstrating wide beta-hemolysis should be suspected of being S. pseudoporcinus and not S. agalactiae.

  13. Multiplex PCR and a chromogenic DNA macroarray for the detection of Listeria monocytogens, Staphylococcus aureus, Streptococcus agalactiae, Enterobacter sakazakii, Escherichia coli O157:H7, Vibrio parahaemolyticus, Salmonella spp. and Pseudomonas fluorescens in milk and meat samples.

    PubMed

    Chiang, Yu-Cheng; Tsen, Hau-Yang; Chen, Hsin-Yen; Chang, Yu-Hsin; Lin, Chien-Ku; Chen, Chih-Yuan; Pai, Wan-Yu

    2012-01-01

    Food products, such as milk and meat products including cheese, milk powder, fermented milk, sausage, etc. are susceptible to the contamination by pathogenic and deteriorative bacteria. These bacteria include Listeria monocytogens, Staphylococcus aureus, Enterobacter sakazakii, Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Streptococcus agalactiae and Pseudomonas fluorescens, etc. Traditional methods for the detection of these microorganisms are laborious and time consuming. Therefore, rapid and accurate diagnostic methods are needed. In this study, we designed the DNA probes and PCR primers for the detection of aforementioned microorganisms. By using two sets of multiplex PCR, followed by a chromogenic macroarray system, these organisms in milk or other food products could be simultaneously detected. When the system was used for the inspection of milk or meat homogenate containing 10(0) target cells per milliliter or gram of the sample, all these bacterial species could be identified after an 8h pre-enrichment step. The system consisting of a multiplex PCR step followed by macroarray allowed us to detect multiple target bacterial species simultaneously without the use of agarose gel electrophoresis. Compared to the commonly used multiplex PCR method, this approach has the additional advantage of detecting more bacterial strains because some bacterial strains generate PCR products with the same molecular sizes which can be differentiated by macroarray but not by electrophoresis. PMID:22101309

  14. Multicenter Study of the Mechanisms of Resistance and Clonal Relationships of Streptococcus agalactiae Isolates Resistant to Macrolides, Lincosamides, and Ketolides in Spain

    PubMed Central

    Gonzalez, J. J.; Andreu, A.

    2005-01-01

    Macrolide, lincosamide, and ketolide mechanisms of resistance and clonal relationships were characterized in a collection of 79 resistant group B streptococcus isolates obtained from neonates or pregnant women. The erm(B), erm(TR), and mef(A) genes were present in 62%, 30.4%, and 3.8% of the isolates, respectively. There was considerable clonal diversity among them. PMID:15917563

  15. Genomics of Streptococcus salivarius, a major human commensal.

    PubMed

    Delorme, Christine; Abraham, Anne-Laure; Renault, Pierre; Guédon, Eric

    2015-07-01

    The salivarius group of streptococci is of particular importance for humans. This group consists of three genetically similar species, Streptococcus salivarius, Streptococcus vestibularis and Streptococcus thermophilus. S. salivarius and S. vestibularis are commensal organisms that may occasionally cause opportunistic infections in humans, whereas S. thermophilus is a food bacterium widely used in dairy production. We developed Multilocus sequence typing (MLST) and comparative genomic analysis to confirm the clear separation of these three species. These analyses also identified a subgroup of four strains, with a core genome diverging by about 10%, in terms of its nucleotide sequence, from that of S. salivarius sensu stricto. S. thermophilus species displays a low level of nucleotide variability, due to its recent emergence with the development of agriculture. By contrast, nucleotide variability is high in the other two species of the salivarius group, reflecting their long-standing association with humans. The species of the salivarius group have genome sizes ranging from the smallest (∼ 1.7 Mb for S. thermophilus) to the largest (∼ 2.3 Mb for S. salivarius) among streptococci, reflecting genome reduction linked to a narrow, nutritionally rich environment for S. thermophilus, and natural, more competitive niches for the other two species. Analyses of genomic content have indicated that the core genes of S. salivarius account for about two thirds of the genome, indicating considerable variability of gene content and differences in potential adaptive features. Furthermore, we showed that the genome of this species is exceptionally rich in genes encoding surface factors, glycosyltransferases and response regulators. Evidence of widespread genetic exchanges was obtained, probably involving a natural competence system and the presence of diverse mobile elements. However, although the S. salivarius strains studied were isolated from several human body-related sites

  16. Genomics of Streptococcus salivarius, a major human commensal.

    PubMed

    Delorme, Christine; Abraham, Anne-Laure; Renault, Pierre; Guédon, Eric

    2015-07-01

    The salivarius group of streptococci is of particular importance for humans. This group consists of three genetically similar species, Streptococcus salivarius, Streptococcus vestibularis and Streptococcus thermophilus. S. salivarius and S. vestibularis are commensal organisms that may occasionally cause opportunistic infections in humans, whereas S. thermophilus is a food bacterium widely used in dairy production. We developed Multilocus sequence typing (MLST) and comparative genomic analysis to confirm the clear separation of these three species. These analyses also identified a subgroup of four strains, with a core genome diverging by about 10%, in terms of its nucleotide sequence, from that of S. salivarius sensu stricto. S. thermophilus species displays a low level of nucleotide variability, due to its recent emergence with the development of agriculture. By contrast, nucleotide variability is high in the other two species of the salivarius group, reflecting their long-standing association with humans. The species of the salivarius group have genome sizes ranging from the smallest (∼ 1.7 Mb for S. thermophilus) to the largest (∼ 2.3 Mb for S. salivarius) among streptococci, reflecting genome reduction linked to a narrow, nutritionally rich environment for S. thermophilus, and natural, more competitive niches for the other two species. Analyses of genomic content have indicated that the core genes of S. salivarius account for about two thirds of the genome, indicating considerable variability of gene content and differences in potential adaptive features. Furthermore, we showed that the genome of this species is exceptionally rich in genes encoding surface factors, glycosyltransferases and response regulators. Evidence of widespread genetic exchanges was obtained, probably involving a natural competence system and the presence of diverse mobile elements. However, although the S. salivarius strains studied were isolated from several human body-related sites

  17. Gene repertoire evolution of Streptococcus pyogenes inferred from phylogenomic analysis with Streptococcus canis and Streptococcus dysgalactiae.

    PubMed

    Lefébure, Tristan; Richards, Vince P; Lang, Ping; Pavinski-Bitar, Paulina; Stanhope, Michael J

    2012-01-01

    Streptococcus pyogenes, is an important human pathogen classified within the pyogenic group of streptococci, exclusively adapted to the human host. Our goal was to employ a comparative evolutionary approach to better understand the genomic events concomitant with S. pyogenes human adaptation. As part of ascertaining these events, we sequenced the genome of one of the potential sister species, the agricultural pathogen S. canis, and combined it in a comparative genomics reconciliation analysis with two other closely related species, Streptococcus dysgalactiae and Streptococcus equi, to determine the genes that were gained and lost during S. pyogenes evolution. Genome wide phylogenetic analyses involving 15 Streptococcus species provided convincing support for a clade of S. equi, S. pyogenes, S. dysgalactiae, and S. canis and suggested that the most likely S. pyogenes sister species was S. dysgalactiae. The reconciliation analysis identified 113 genes that were gained on the lineage leading to S. pyogenes. Almost half (46%) of these gained genes were phage associated and 14 showed significant matches to experimentally verified bacteria virulence factors. Subsequent to the origin of S. pyogenes, over half of the phage associated genes were involved in 90 different LGT events, mostly involving different strains of S. pyogenes, but with a high proportion involving the horse specific pathogen S. equi subsp. equi, with the directionality almost exclusively (86%) in the S. pyogenes to S. equi direction. Streptococcus agalactiae appears to have played an important role in the evolution of S. pyogenes with a high proportion of LGTs originating from this species. Overall the analysis suggests that S. pyogenes adaptation to the human host was achieved in part by (i) the integration of new virulence factors (e.g. speB, and the sal locus) and (ii) the construction of new regulation networks (e.g. rgg, and to some extent speB).

  18. Gene Repertoire Evolution of Streptococcus pyogenes Inferred from Phylogenomic Analysis with Streptococcus canis and Streptococcus dysgalactiae

    PubMed Central

    Lefébure, Tristan; Richards, Vince P.; Lang, Ping; Pavinski-Bitar, Paulina; Stanhope, Michael J.

    2012-01-01

    Streptococcus pyogenes, is an important human pathogen classified within the pyogenic group of streptococci, exclusively adapted to the human host. Our goal was to employ a comparative evolutionary approach to better understand the genomic events concomitant with S. pyogenes human adaptation. As part of ascertaining these events, we sequenced the genome of one of the potential sister species, the agricultural pathogen S. canis, and combined it in a comparative genomics reconciliation analysis with two other closely related species, Streptococcus dysgalactiae and Streptococcus equi, to determine the genes that were gained and lost during S. pyogenes evolution. Genome wide phylogenetic analyses involving 15 Streptococcus species provided convincing support for a clade of S. equi, S. pyogenes, S. dysgalactiae, and S. canis and suggested that the most likely S. pyogenes sister species was S. dysgalactiae. The reconciliation analysis identified 113 genes that were gained on the lineage leading to S. pyogenes. Almost half (46%) of these gained genes were phage associated and 14 showed significant matches to experimentally verified bacteria virulence factors. Subsequent to the origin of S. pyogenes, over half of the phage associated genes were involved in 90 different LGT events, mostly involving different strains of S. pyogenes, but with a high proportion involving the horse specific pathogen S. equi subsp. equi, with the directionality almost exclusively (86%) in the S. pyogenes to S. equi direction. Streptococcus agalactiae appears to have played an important role in the evolution of S. pyogenes with a high proportion of LGTs originating from this species. Overall the analysis suggests that S. pyogenes adaptation to the human host was achieved in part by (i) the integration of new virulence factors (e.g. speB, and the sal locus) and (ii) the construction of new regulation networks (e.g. rgg, and to some extent speB). PMID:22666370

  19. Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections.

    PubMed

    Shewmaker, P L; Whitney, A M; Humrighouse, B W

    2016-03-01

    Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324(T), 97.9% similarity to S. canis ATCC 43496(T), and 97.8% similarity to S. ictaluri ATCC BAA-1300(T). A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844(T) = CCUG 67100(T) = LMG 28801(T).

  20. Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections

    PubMed Central

    Whitney, A. M.; Humrighouse, B. W.

    2016-01-01

    Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324T, 97.9% similarity to S. canis ATCC 43496T, and 97.8% similarity to S. ictaluri ATCC BAA-1300T. A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844T = CCUG 67100T = LMG 28801T. PMID:26763962

  1. First case of a dog bite wound infection caused by Streptococcus minor in human.

    PubMed

    Tré-Hardy, M; Saussez, T; Yombi, J C; Rodriguez-Villalobos, H

    2016-11-01

    We report the first case of human infection caused by Streptococcus minor in a 51-year-old immunocompetent woman admitted for dog bite injuries. At present, the role of Streptococcus minor in bite wound infections is unknown. Further studies on virulence factors are needed to elucidate its pathogenicity mechanisms. PMID:27688883

  2. Human plasma fibronectin inhibits adherence of Streptococcus pyogenes to hexadecane.

    PubMed Central

    Courtney, H S; Ofek, I; Simpson, W A; Whitnack, E; Beachey, E H

    1985-01-01

    The effect of human plasma fibronectin on the adherence of Streptococcus pyogenes to hexadecane droplets was investigated. Fibronectin blocked the adherence of streptococci to hexadecane in a dose-dependent manner. The inhibitory effect resulted from the binding of fibronectin to the streptococcal cells; radiolabeled fibronectin failed to bind to the hexadecane but bound readily to untreated streptococci. Chemical treatments of streptococci that decreased streptococcal binding of fibronectin also decreased their binding to hexadecane. Pretreatment of fibronectin with lipoteichoic acid blocked the binding of fibronectin to streptococci and abolished its ability to inhibit streptococcal adherence to hexadecane in a dose-related manner. In contrast, wheat germ agglutinin, which binds to N-acetylglucosamine on the surface of S. pyogenes cells, failed to alter hexadecane adherence. The data suggest that fibronectin binds to lipoteichoic acid on the surface of the streptococci, thereby preventing lipoteichoic acid from interacting with the hexadecane phase. PMID:3880729

  3. Cytosolic Replication of Group A Streptococcus in Human Macrophages

    PubMed Central

    O’Neill, Alan M.; Thurston, Teresa L. M.

    2016-01-01

    ABSTRACT As key components of innate immune defense, macrophages are essential in controlling bacterial pathogens, including group A Streptococcus (GAS). Despite this, only a limited number of studies have analyzed the recovery of GAS from within human neutrophils and macrophages. Here, we determined the intracellular fate of GAS in human macrophages by using several quantitative approaches. In both U937 and primary human macrophages, the appearance over time of long GAS chains revealed that despite GAS-mediated cytotoxicity, replication occurred in viable, propidium iodide-negative macrophages. Whereas the major virulence factor M1 did not contribute to bacterial growth, a GAS mutant strain deficient in streptolysin O (SLO) was impaired for intracellular replication. SLO promoted bacterial escape from the GAS-containing vacuole (GCV) into the macrophage cytosol. Up to half of the cytosolic GAS colocalized with ubiquitin and p62, suggesting that the bacteria were targeted by the autophagy machinery. Despite this, live imaging of U937 macrophages revealed proficient replication of GAS after GCV rupture, indicating that escape from the GCV is important for growth of GAS in macrophages. Our results reveal that GAS can replicate within viable human macrophages, with SLO promoting GCV escape and cytosolic growth, despite the recruitment of autophagy receptors to bacteria. PMID:27073088

  4. Adaptation of Group A Streptococcus to Human Amniotic Fluid

    PubMed Central

    Sitkiewicz, Izabela; Green, Nicole M.; Guo, Nina; Bongiovanni, Ann M.; Witkin, Steven S.; Musser, James M.

    2010-01-01

    Background For more than 100 years, group A Streptococcus has been identified as a cause of severe and, in many cases, fatal infections of the female urogenital tract. Due to advances in hospital hygiene and the advent of antibiotics, this type of infection has been virtually eradicated. However, within the last three decades there has been an increase in severe intra- and post-partum infections attributed to GAS. Methodology We hypothesized that GAS alters its transcriptome to survive in human amniotic fluid (AF) and cause disease. To identify genes that were up or down regulated in response to growth in AF, GAS was grown in human AF or standard laboratory media (THY) and samples for expression microarray analysis were collected during mid-logarithmic, late-logarithmic, and stationary growth phases. Microarray analysis was performed using a custom Affymetrix chip and normalized hybridization values derived from three biological replicates were collected at each growth point. Ratios of AF/THY above a 2-fold change and P-value <0.05 were considered significant. Principal Findings The majority of changes in the GAS transcriptome involved down regulation of multiple adhesins and virulence factors and activation of the stress response. We observed significant changes in genes involved in the arginine deiminase pathway and in the nucleotide de novo synthesis pathway. Conclusions/Significance Our work provides new insight into how pathogenic bacteria respond to their environment to establish infection and cause disease. PMID:20352104

  5. Association of Streptococcus mutans with Human Dental Decay

    PubMed Central

    Loesche, W. J.; Rowan, J.; Straffon, L. H.; Loos, P. J.

    1975-01-01

    The association of Streptococcus mutans with human dental decay was investigated by using several types of samples: (i) paraffin-stimulated saliva samples taken from children with from 0 to 15 decayed teeth; (ii) pooled occlusal and approximal plaque taken from children with no decayed or filled teeth, or from children with rampant caries of 10 or more teeth; (iii) plaque removed from single occlusal fissures that were either carious or noncarious. The results showed a significant association between plaque levels of S. mutans and caries. The strongest association, P < 0.0001, was found when plaque was removed from single occlusal fissures. Seventy-one percent of the carious fissures had S. mutans accounting for more than 10% of the viable flora, whereas 70% of the fissures that were caries free had no detectable S. mutans. Sixty-five percent of the pooled plaque samples from the children with rampant caries had S. mutans accounting for more than 10% of the viable flora, whereas 40% of the pooled samples from children that were caries free had no detectable S. mutans. Saliva samples tended to have low levels of S. mutans and were equivocal in demonstrating a relationship between S. mutans and caries. PMID:1140847

  6. Role of human milk oligosaccharides in Group B Streptococcus colonisation.

    PubMed

    Andreas, Nicholas J; Al-Khalidi, Asmaa; Jaiteh, Mustapha; Clarke, Edward; Hyde, Matthew J; Modi, Neena; Holmes, Elaine; Kampmann, Beate; Mehring Le Doare, Kirsty

    2016-08-01

    Group B Streptococcus (GBS) infection is a major cause of morbidity and mortality in infants. The major risk factor for GBS disease is maternal and subsequent infant colonisation. It is unknown whether human milk oligosaccharides (HMOs) protect against GBS colonisation. HMO production is genetically determined and linked to the Lewis antigen system. We aimed to investigate the association between HMOs and infant GBS colonisation between birth and postnatal day 90. Rectovaginal swabs were collected at delivery, as well as colostrum/breast milk, infant nasopharyngeal and rectal swabs at birth, 6 days and days 60-89 postpartum from 183 Gambian mother/infant pairs. GBS colonisation and serotypes were determined using culture and PCR. (1)H nuclear magnetic resonance spectroscopy was used to characterise the mother's Lewis status and HMO profile in breast milk. Mothers who were Lewis-positive were significantly less likely to be colonised by GBS (X (2)=12.50, P<0.001). Infants of Lewis-positive mothers were less likely GBS colonised at birth (X (2)=4.88 P=0.03) and more likely to clear colonisation between birth and days 60-89 than infants born to Lewis-negative women (P=0.05). There was no association between Secretor status and GBS colonisation. In vitro work revealed that lacto-N-difucohexaose I (LNDFHI) correlated with a reduction in the growth of GBS. Our results suggest that HMO such as LNDFHI may be a useful adjunct in reducing maternal and infant colonisation and hence invasive GBS disease. Secretor status offers utility as a stratification variable in GBS clinical trials. PMID:27588204

  7. Role of human milk oligosaccharides in Group B Streptococcus colonisation

    PubMed Central

    Andreas, Nicholas J; Al-Khalidi, Asmaa; Jaiteh, Mustapha; Clarke, Edward; Hyde, Matthew J; Modi, Neena; Holmes, Elaine; Kampmann, Beate; Mehring Le Doare, Kirsty

    2016-01-01

    Group B Streptococcus (GBS) infection is a major cause of morbidity and mortality in infants. The major risk factor for GBS disease is maternal and subsequent infant colonisation. It is unknown whether human milk oligosaccharides (HMOs) protect against GBS colonisation. HMO production is genetically determined and linked to the Lewis antigen system. We aimed to investigate the association between HMOs and infant GBS colonisation between birth and postnatal day 90. Rectovaginal swabs were collected at delivery, as well as colostrum/breast milk, infant nasopharyngeal and rectal swabs at birth, 6 days and days 60–89 postpartum from 183 Gambian mother/infant pairs. GBS colonisation and serotypes were determined using culture and PCR. 1H nuclear magnetic resonance spectroscopy was used to characterise the mother's Lewis status and HMO profile in breast milk. Mothers who were Lewis-positive were significantly less likely to be colonised by GBS (X2=12.50, P<0.001). Infants of Lewis-positive mothers were less likely GBS colonised at birth (X2=4.88 P=0.03) and more likely to clear colonisation between birth and days 60–89 than infants born to Lewis-negative women (P=0.05). There was no association between Secretor status and GBS colonisation. In vitro work revealed that lacto-N-difucohexaose I (LNDFHI) correlated with a reduction in the growth of GBS. Our results suggest that HMO such as LNDFHI may be a useful adjunct in reducing maternal and infant colonisation and hence invasive GBS disease. Secretor status offers utility as a stratification variable in GBS clinical trials. PMID:27588204

  8. Complete genome sequence of Streptococcus salivarius PS4, a strain isolated from human milk.

    PubMed

    Martín, Virginia; Maldonado-Barragán, Antonio; Jiménez, Esther; Ruas-Madiedo, Patricia; Fernández, Leónides; Rodríguez, Juan M

    2012-08-01

    Streptococcus salivarius is a commensal species commonly found in the human oropharyngeal tract. Some strains of this species have been developed for use as oral probiotics, while others have been associated with a variety of opportunistic human infections. Here, we report the complete sequence of strain PS4, which was isolated from breast milk of a healthy woman. PMID:22843595

  9. Complete Genome Sequence of Streptococcus salivarius PS4, a Strain Isolated from Human Milk

    PubMed Central

    Martín, Virginia; Maldonado-Barragán, Antonio; Jiménez, Esther; Ruas-Madiedo, Patricia; Fernández, Leónides

    2012-01-01

    Streptococcus salivarius is a commensal species commonly found in the human oropharyngeal tract. Some strains of this species have been developed for use as oral probiotics, while others have been associated with a variety of opportunistic human infections. Here, we report the complete sequence of strain PS4, which was isolated from breast milk of a healthy woman. PMID:22843595

  10. Capsular polysaccharide of Group B Streptococcus mediates biofilm formation in the presence of human plasma.

    PubMed

    Xia, Fan Di; Mallet, Adeline; Caliot, Elise; Gao, Cherry; Trieu-Cuot, Patrick; Dramsi, Shaynoor

    2015-01-01

    Group B Streptococcus (GBS) is an asymptomatic colonizer of human mucosal surfaces that is responsible for sepsis and meningitis in neonates. Bacterial persistence and pathogenesis often involves biofilm formation. We previously showed that biofilm formation in medium supplemented with glucose is mediated by the PI-2a pilus. Here, biofilm formation was tested in cell culture medium supplemented with human plasma. GBS strains were able to form biofilms in these conditions unlike Group A Streptococcus (GAS) or Staphylococcus aureus. Analysis of mutants impaired for various surface components revealed that the GBS capsule is a key component in this process.

  11. 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.

  12. 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

  13. 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

  14. Comparative Genomics Analysis of Streptococcus Isolates from the Human Small Intestine Reveals their Adaptation to a Highly Dynamic Ecosystem

    PubMed Central

    Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

    2013-01-01

    The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine. PMID:24386196

  15. Comparative genomics analysis of Streptococcus isolates from the human small intestine reveals their adaptation to a highly dynamic ecosystem.

    PubMed

    Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

    2013-01-01

    The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine.

  16. 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

  17. 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.

  18. Complete Genome Sequence of Streptococcus salivarius HSISS4, a Human Commensal Bacterium Highly Prevalent in the Digestive Tract.

    PubMed

    Mignolet, Johann; Fontaine, Laetitia; Kleerebezem, Michiel; Hols, Pascal

    2016-01-01

    The human commensal bacterium Streptococcus salivarius plays a major role in the equilibrium of microbial communities of the digestive tract. Here, we report the first complete genome sequence of a Streptococcus salivarius strain isolated from the small intestine, namely, HSISS4. Its circular chromosome comprises 1,903 coding sequences and 2,100,988 nucleotides. PMID:26847886

  19. Complete Genome Sequence of Streptococcus salivarius HSISS4, a Human Commensal Bacterium Highly Prevalent in the Digestive Tract

    PubMed Central

    Fontaine, Laetitia; Kleerebezem, Michiel

    2016-01-01

    The human commensal bacterium Streptococcus salivarius plays a major role in the equilibrium of microbial communities of the digestive tract. Here, we report the first complete genome sequence of a Streptococcus salivarius strain isolated from the small intestine, namely, HSISS4. Its circular chromosome comprises 1,903 coding sequences and 2,100,988 nucleotides. PMID:26847886

  20. Infection of human keratinocytes by Streptococcus dysgalactiae subspecies dysgalactiae isolated from milk of the bovine udder.

    PubMed

    Roma-Rodrigues, Catarina; Alves-Barroco, Cynthia; Raposo, Luís R; Costa, Mafalda N; Fortunato, Elvira; Baptista, Pedro Viana; Fernandes, Alexandra R; Santos-Sanches, Ilda

    2016-04-01

    Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) are considered exclusive animal pathogens; however, a putative zoonotic upper limb cellulitis, a prosthetic joint infection and an infective endocarditis were described in humans. To unravel if bovine SDSD isolates are able to infect human cells, the adherence and internalization to human primary keratinocytes of two bovine SDSD strains isolated from milk collected from udder were analyzed. Bacterial adhesion assays and confocal microscopy indicate a high adherence and internalization of SDSD isolates to human cells, suggesting for the first time the ability of bovine isolates to infect human cells. PMID:26655883

  1. Streptococcus oligofermentans sp. nov., a novel oral isolate from caries-free humans.

    PubMed

    Tong, Huichun; Gao, Xuejun; Dong, Xiuzhu

    2003-07-01

    Five streptococcal strains were isolated from dental plaque and saliva of caries-free humans. The cells were gram-positive, non-spore-forming, non-motile cocci that were arranged in short chains. The strains were catalase-negative, facultatively anaerobic and produced lactic acid exclusively from glucose fermentation. Biochemical analysis that used both conventional methods and the commercial API 20 Strep system showed that the five strains fermented only a few kinds of sugar. The mean DNA G + C content of the five novel strains was 39.5 +/- 0.8 mol%. Phylogenetic analysis based on 16S rDNA sequence homology indicated that the new isolates represented a novel member of the mitis group of the genus Streptococcus, related most closely to the recently described species Streptococcus sinensis. DNA-DNA relatedness between novel strain LMG 21535T and type strains of phylogenetically related species of oral streptococci was 7.1-16.4%. Therefore a novel Streptococcus species, Streptococcus oligofermentans sp. nov., is proposed. The type strain is LMG 21535T=AS 1.3089T.

  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. Streptococcus agalactie involved in the etiology of sexually transmitted diseases.

    PubMed

    Frey, Marcos Noronha; Ioppi, Ana Elisa Empinotti; Bonamigo, Renan Rangel; Prado, Guilherme Pinheiro

    2011-01-01

    Streptococcus agalactiae is an important microorganism involved in a number of conditions in pregnant women, newborns, elderly people (over 65 years of age) and individuals with chronic disabling illnesses. This pathogen is infrequently found among patients outside this age range or clinical profile(1-5) and is rarely reported in the etiology of sexually transmitted diseases. Here we describe a case of an otherwise healthy 19 year-old male, who presented with ulcerative genital and oral lesions in association with urethral and ocular discharge, suggestive of Streptococcus agalactiae infection acquired through sexual contact.

  4. Pathogenesis of Streptococcus urinary tract infection depends on bacterial strain and β-hemolysin/cytolysin that mediates cytotoxicity, cytokine synthesis, inflammation and virulence

    PubMed Central

    Leclercq, Sophie Y.; Sullivan, Matthew J.; Ipe, Deepak S.; Smith, Joshua P.; Cripps, Allan W.; Ulett, Glen C.

    2016-01-01

    Streptococcus agalactiae can cause urinary tract infection (UTI) including cystitis and asymptomatic bacteriuria (ABU). The early host-pathogen interactions that occur during S. agalactiae UTI and subsequent mechanisms of disease pathogenesis are poorly defined. Here, we define the early interactions between human bladder urothelial cells, monocyte-derived macrophages, and mouse bladder using uropathogenic S. agalactiae (UPSA) 807 and ABU-causing S. agalactiae (ABSA) 834 strains. UPSA 807 adhered, invaded and killed bladder urothelial cells more efficiently compared to ABSA 834 via mechanisms including low-level caspase-3 activation, and cytolysis, according to lactate dehydrogenase release measures and cell viability. Severe UPSA 807-induced cytotoxicity was mediated entirely by the bacterial β-hemolysin/cytolysin (β-H/C) because an β-H/C-deficient UPSA 807 isogenic mutant, UPSA 807ΔcylE, was not cytotoxic in vitro; the mutant was also significantly attenuated for colonization in the bladder in vivo. Analysis of infection-induced cytokines, including IL-8, IL-1β, IL-6 and TNF-α in vitro and in vivo revealed that cytokine and chemokine responses were dependent on expression of β-H/C that also elicited severe bladder neutrophilia. Thus, virulence of UPSA 807 encompasses adhesion to, invasion of and killing of bladder cells, pro-inflammatory cytokine/chemokine responses that elicit neutrophil infiltration, and β-H/C-mediated subversion of innate immune-mediated bacterial clearance from the bladder. PMID:27383371

  5. Streptococcus massiliensis in the human mouth: a phylogenetic approach for the inference of bacterial habitats.

    PubMed

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

    2015-12-29

    Streptococcus is a diverse bacterial lineage. Species of this genus occupy a myriad of environments inside humans and other animals. Despite the elucidation of several of these habitats, many remain to be identified. Here, we explore a methodological approach to reveal unknown bacterial environments. Specifically, we inferred the phylogeny of the Mitis group by analyzing the sequences of eight genes. In addition, information regarding habitat use of species belonging to this group was obtained from the scientific literature. The oral cavity emerged as a potential, previously unknown, environment of Streptococcus massiliensis. This phylogeny-based prediction was confirmed by species-specific polymerase chain reaction (PCR) amplification. We propose employing a similar approach, i.e., use of bibliographic data and molecular phylogenetics as predictive methods, and species-specific PCR as confirmation, in order to reveal other unknown habitats in further bacterial taxa.

  6. Novel bacteriophage lysin with broad lytic activity protects against mixed infection by Streptococcus pyogenes and methicillin-resistant Staphylococcus aureus.

    PubMed

    Gilmer, Daniel B; Schmitz, Jonathan E; Euler, Chad W; Fischetti, Vincent A

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pyogenes (group A streptococcus [GrAS]) cause serious and sometimes fatal human diseases. They are among the many Gram-positive pathogens for which resistance to leading antibiotics has emerged. As a result, alternative therapies need to be developed to combat these pathogens. We have identified a novel bacteriophage lysin (PlySs2), derived from a Streptococcus suis phage, with broad lytic activity against MRSA, vancomycin-intermediate S. aureus (VISA), Streptococcus suis, Listeria, Staphylococcus simulans, Staphylococcus epidermidis, Streptococcus equi, Streptococcus agalactiae (group B streptococcus [GBS]), S. pyogenes, Streptococcus sanguinis, group G streptococci (GGS), group E streptococci (GES), and Streptococcus pneumoniae. PlySs2 has an N-terminal cysteine-histidine aminopeptidase (CHAP) catalytic domain and a C-terminal SH3b binding domain. It is stable at 50 °C for 30 min, 37 °C for >24 h, 4°C for 15 days, and -80 °C for >7 months; it maintained full activity after 10 freeze-thaw cycles. PlySs2 at 128 μg/ml in vitro reduced MRSA and S. pyogenes growth by 5 logs and 3 logs within 1 h, respectively, and exhibited a MIC of 16 μg/ml for MRSA. A single, 2-mg dose of PlySs2 protected 92% (22/24) of the mice in a bacteremia model of mixed MRSA and S. pyogenes infection. Serially increasing exposure of MRSA and S. pyogenes to PlySs2 or mupirocin resulted in no observed resistance to PlySs2 and resistance to mupirocin. To date, no other lysin has shown such notable broad lytic activity, stability, and efficacy against multiple, leading, human bacterial pathogens; as such, PlySs2 has all the characteristics to be an effective therapeutic.

  7. Identification of Streptococcus parasanguinis DNA contamination in human buccal DNA samples

    PubMed Central

    2013-01-01

    Background The use of buccal swabs in clinical and scientific studies is a very popular method of collecting DNA, due to its non-invasive nature of collection. However, contamination of the DNA sample may interfere with analysis. Findings Here we report the finding of Streptococcus parasanguinis bacterial DNA contamination in human buccal DNA samples, which led to preferential amplification of bacterial sequence with PCR primers designed against human sequence. Conclusion Contamination of buccal-derived DNA with bacterial DNA can be significant, and may influence downstream genetic analysis. One needs to be aware of possible bacterial contamination when interpreting abnormal findings following PCR amplification of buccal swab DNA samples. PMID:24266944

  8. LambdaSa1 and LambdaSa2 Prophage Lysins of Streptococcus agalactiae▿

    PubMed Central

    Pritchard, David G.; Dong, Shengli; Kirk, Marion C.; Cartee, Robert T.; Baker, John R.

    2007-01-01

    Putative N-acetylmuramyl-l-alanine amidase genes from LambdaSa1 and LambdaSa2 prophages of Streptococcus agalactiae were cloned and expressed in Escherichia coli. The purified enzymes lysed the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae, and Staphylococcus aureus. The peptidoglycan digestion products in the cell wall lysates were not consistent with amidase activity. Instead, the structure of the muropeptide digestion fragments indicated that both the LambdaSa1 and LambdaSa2 lysins exhibited γ-d-glutaminyl-l-lysine endopeptidase activity. The endopeptidase cleavage specificity of the lysins was confirmed using a synthetic peptide substrate corresponding to a portion of the stem peptide and cross bridge of Streptococcus agalactiae peptidoglycan. The LambdaSa2 lysin also displayed β-d-N-acetylglucosaminidase activity. PMID:17905888

  9. Multilocus Sequence Analysis of Streptococcus canis Confirms the Zoonotic Origin of Human Infections and Reveals Genetic Exchange with Streptococcus dysgalactiae subsp. equisimilis

    PubMed Central

    Pinho, M. D.; Matos, S. C.; Pomba, C.; Lübke-Becker, A.; Wieler, L. H.; Preziuso, S.; Melo-Cristino, J.

    2013-01-01

    Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection. PMID:23345291

  10. Multilocus sequence analysis of Streptococcus canis confirms the zoonotic origin of human infections and reveals genetic exchange with Streptococcus dysgalactiae subsp. equisimilis.

    PubMed

    Pinho, M D; Matos, S C; Pomba, C; Lübke-Becker, A; Wieler, L H; Preziuso, S; Melo-Cristino, J; Ramirez, M

    2013-04-01

    Streptococcus canis is an animal pathogen that occasionally causes human infections. Isolates recovered from infections of animals (n = 78, recovered from 2000 to 2010 in three European countries, mainly from house pets) and humans (n = 7, recovered from 2006 to 2010 in Portugal) were identified by phenotypic and genotypic methods and characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and emm typing. S. canis isolates presented considerable variability in biochemical profiles and 16S rRNA. Resistance to antimicrobial agents was low, with the most significant being tet(M)- and tet(O)-mediated tetracycline resistance. MLST analysis revealed a polyclonal structure of the S. canis population causing infections, where the same genetic lineages were found infecting house pets and humans and were disseminated in distinct geographic locations. Phylogenetic analysis indicated that S. canis was a divergent taxon of the sister species Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis and found evidence of acquisition of genetic material by S. canis from S. dysgalactiae subsp. equisimilis. PFGE confirmed the MLST findings, further strengthening the similarity between animal and human isolates. The presence of emm-like genes was restricted to a few isolates and correlated with some MLST-based genetic lineages, but none of the human isolates could be emm typed. Our data show that S. canis isolates recovered from house pets and humans constitute a single population and demonstrate that isolates belonging to the main genetic lineages identified have the ability to infect the human host, providing strong evidence for the zoonotic nature of S. canis infection.

  11. Transmission of Streptococcus equi subspecies zooepidemicus infection from horses to humans.

    PubMed

    Pelkonen, Sinikka; Lindahl, Susanne B; Suomala, Päivi; Karhukorpi, Jari; Vuorinen, Sakari; Koivula, Irma; Väisänen, Tia; Pentikäinen, Jaana; Autio, Tiina; Tuuminen, Tamara

    2013-07-01

    Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen's epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates from horses. The isolates were analyzed by using pulsed-field gel electrophoresis, multilocus sequence typing, and sequencing of the szP gene. Molecular typing methods showed that human and equine isolates were identical or closely related. These results emphasize that S. zooepidemicus transmitted from horses can lead to severe infections in humans. As leisure and professional equine sports continue to grow, this infection should be recognized as an emerging zoonosis.

  12. Transmission of Streptococcus equi Subspecies zooepidemicus Infection from Horses to Humans

    PubMed Central

    Lindahl, Susanne B.; Suomala, Päivi; Karhukorpi, Jari; Vuorinen, Sakari; Koivula, Irma; Väisänen, Tia; Pentikäinen, Jaana; Autio, Tiina; Tuuminen, Tamara

    2013-01-01

    Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen’s epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates from horses. The isolates were analyzed by using pulsed-field gel electrophoresis, multilocus sequence typing, and sequencing of the szP gene. Molecular typing methods showed that human and equine isolates were identical or closely related. These results emphasize that S. zooepidemicus transmitted from horses can lead to severe infections in humans. As leisure and professional equine sports continue to grow, this infection should be recognized as an emerging zoonosis. PMID:23777752

  13. Streptococcus thermophilus CRISPR-Cas9 Systems Enable Specific Editing of the Human Genome.

    PubMed

    Müller, Maximilian; Lee, Ciaran M; Gasiunas, Giedrius; Davis, Timothy H; Cradick, Thomas J; Siksnys, Virginijus; Bao, Gang; Cathomen, Toni; Mussolino, Claudio

    2016-03-01

    RNA-guided nucleases (RGNs) based on the type II CRISPR-Cas9 system of Streptococcus pyogenes (Sp) have been widely used for genome editing in experimental models. However, the nontrivial level of off-target activity reported in several human cells may hamper clinical translation. RGN specificity depends on both the guide RNA (gRNA) and the protospacer adjacent motif (PAM) recognized by the Cas9 protein. We hypothesized that more stringent PAM requirements reduce the occurrence of off-target mutagenesis. To test this postulation, we generated RGNs based on two Streptococcus thermophilus (St) Cas9 proteins, which recognize longer PAMs, and performed a side-by-side comparison of the three RGN systems targeted to matching sites in two endogenous human loci, PRKDC and CARD11. Our results demonstrate that in samples with comparable on-target cleavage activities, significantly lower off-target mutagenesis was detected using St-based RGNs as compared to the standard Sp-RGNs. Moreover, similarly to SpCas9, the StCas9 proteins accepted truncated gRNAs, suggesting that the specificities of St-based RGNs can be further improved. In conclusion, our results show that Cas9 proteins with longer or more restrictive PAM requirements provide a safe alternative to SpCas9-based RGNs and hence a valuable option for future human gene therapy applications. PMID:26658966

  14. Novel impedimetric immunosensor for detection of pathogenic bacteria Streptococcus pyogenes in human saliva.

    PubMed

    Ahmed, Asif; Rushworth, Jo V; Wright, John D; Millner, Paul A

    2013-12-17

    Streptococcus pyogenes , also known as group A streptococcus (GAS), is a Gram positive human pathogen responsible for invasive and noninvasive human infections with a high incidence rate. Traditional detection methods involve cell culture and PCR, which are limited by long processing times or the need for high cost equipment. Impedance-based electrochemical immunosensors provide an alternative by which precise and rapid quantitative detection of the organism can help with rapid clinical decisions. To bring a biosensor for point-of-care applications to market, strict optimization of each level of construction and operation is required. In this paper, commercial screen-printed gold electrodes have been used to construct polytyramine (Ptyr)-based immunosensors. Biotin tagged whole antibodies against S. pyogenes were conjugated to Ptyr amine group via biotin-NeutrAvidin coupling. Sensors were optimized at each level of construction, particularly for Ptyr electrodeposition and antibody concentration, to optimize signal and specificity. Scanning electron microscopy, fluorescence microscopy, and on-sensor analysis (HRP conjugated enhanced chemiluminescence-based semiquantitative method) to detect Ptyr surface amine and bound antibody were performed as supporting techniques. Cumulative and single shot incubations had shown detection range of 100 to 10(5) cells per 10 μL and 100 to 10(4) cells per 10 μL of bacteria in PBS, respectively. Sensors were also able to specifically detect S. pyogenes in 50% (v/v) human saliva, with good selectivity and low cross-reactivity.

  15. Degradation of human immunoglobulins by proteases from Streptococcus pneumoniae obtained from various human sources.

    PubMed Central

    Wikström, M B; Dahlén, G; Kaijser, B; Nygren, H

    1984-01-01

    The ability of Streptococcus pneumoniae to degrade human secretory immunoglobulin A (S-IgA), IgG, and IgM was tested in 102 strains by use of the thin-layer enzyme assay cultivation technique. The strains were isolated from patients with acute phases of otitis media, meningitis, and pneumonia as well as from symptomless carriers. An ability to degrade S-IgA, IgG, and IgM was revealed in 50, 84, and 96 strains, respectively. An IgG- and IgM-degrading ability of S. pneumoniae has not previously been reported. A concurrent degradation of the three immunoglobulins was revealed in 38 strains; degradation of two of them was revealed in 54 strains, and degradation of only one of them was revealed in 9 strains. One strain failed to degrade any of the immunoglobulins. Correlations were not found between the ability of the S. pneumoniae strains to degrade S-IgA, IgG, or IgM and the serotype affiliation or between the ability to degrade IgG or IgM and the origin of strains. However, the ability to degrade S-IgA was evident more often in strains isolated from symptomless carriers and from bronchial secretions of patients with acute pneumonia than it was in strains from patients with acute meningitis or acute otitis media or from the blood of patients with acute pneumonia. These latter findings may indicate a biological significance of S-IgA-degrading ability in bacterial colonization of mucosal surfaces. Images PMID:6368393

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

    PubMed

    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

    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

  17. 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

  18. Induction of a putative laminin-binding protein of Streptococcus gordonii in human infective endocarditis.

    PubMed Central

    Sommer, P; Gleyzal, C; Guerret, S; Etienne, J; Grimaud, J A

    1992-01-01

    There is evidence to suggest that the virulence of Streptococcus strains in infective endocarditis might be due to the expression of binding sites for the extracellular matrix proteins of damaged valves. In this communication, we draw attention to one laminin-binding protein from a strain of Streptococcus gordonii isolated from a patient with human endocarditis. This 145-kDa protein was found on the cell wall of the bacterium. The level of expression of this binding protein might be regulated by the presence of extracellular matrix proteins: the protein was lacking after in vitro selection of laminin, collagen I, and fibronectin nonbinding variants, and it was recovered after growth of the variants when laminin or collagen I was added to the growth medium. It was also missing after 10 subcultures in minimal medium, indicating some positive control. Furthermore, the 145-kDa protein was recognized as a major antigen by sera from patients treated for streptococcal infective endocarditis, while sera from patients with valvulopathies gave only slight recognition, suggesting an increase of the expression of this protein during infective endocarditis. It was also shown that the 145-kDa protein carried a collagen I-like determinant detected with anti-human collagen I antibodies. Images PMID:1530927

  19. Epidemiology, clinical manifestations, and outcomes of Streptococcus suis infection in humans.

    PubMed

    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; Hirayama, Kenji

    2014-07-01

    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.

  20. Effects of xylitol on the acid production activity from sorbitol by Streptococcus mutans and human dental plaque.

    PubMed

    Sasaki, N; Topitsoglou, V; Frostell, G

    1983-01-01

    -A method for the determination of acid production from 20-25 mg (wet weight) of Streptococcus mutans and 12-33 mg (wet weight) of human dental plaque is described. After endogenous acid production had been followed, either sorbitol or xylitol or a mixture of sorbitol and xylitol (2:1) was added. After about ten minutes glucose, sucrose or Palatinose were added for a vitality test. Addition of xylitol to the bacterial suspension caused inhibition of acid production from sorbitol by Streptococcus mutans grown on sorbitol or a mixture of sorbitol and glucose. It was also observed that it had a similar effect on acid production from sorbitol in suspensions of dental plaque with few exceptions. On the other hand, Streptococcus mutans cells grown on glucose, sucrose and xylitol media, produced no or insignificant amounts of acid from sorbitol. Streptococcus mutans cells grown on media containing glucose, sucrose, sorbitol and a mixture of sorbitol and glucose generally formed a large amount of acid from glucose and sucrose after the addition of sorbitol and xylitol. However, Streptococcus mutans cells grown on a medium containing xylitol and the mixture of sorbitol and xylitol formed less acid from glucose. The acid production activity from sorbitol in suspensions of dental plaque after the xylitol addition was somewhat lower than the acid production from sorbitol alone (p less than 0.02).

  1. Nasopharyngeal carriage of Streptococcus pneumoniae in adults infected with human immunodeficiency virus in Jakarta, Indonesia.

    PubMed

    Harimurti, Kuntjoro; Saldi, Siti R F; Dewiasty, Esthika; Khoeri, Miftahuddin M; Yunihastuti, Evi; Putri, Tiara; Tafroji, Wisnu; Safari, Dodi

    2016-01-01

    This study investigated the distribution of serotype and antimicrobial susceptibility of Streptococcus pneumoniae carried by adults infected with human immunodeficiency virus (HIV) in Jakarta, Indonesia. Specimens of nasopharyngeal swab were collected from 200 HIV infected adults aged 21 to 63 years. Identification of S. pneumoniae was done by optochin susceptibility test and PCR for the presence of psaA and lytA genes. Serotyping was performed with sequential multiplex PCR and antibiotic susceptibility with the disk diffusion method. S. pneumoniae strains were carried by 10% adults with serotype 6A/B 20% was common serotype among cultured strains in 20 adults. Most of isolates were susceptible to chloramphenicol (80%) followed by clindamycin (75%), erythromycin (75%), penicillin (55%), and tetracycline (50%). This study found resistance to sulphamethoxazole/trimethoprim was most common with only 15% of strains being susceptible. High non-susceptibility to sulphamethoxazole/trimethoprim was observed in S. pneumoniae strains carried by HIV infected adults in Jakarta, Indonesia.

  2. Human bacterial arthritis caused by Streptococcus zooepidemicus: report of a case.

    PubMed

    Friederichs, Jan; Hungerer, Sven; Werle, Regina; Militz, Matthias; Bühren, Volker

    2010-09-01

    Septic arthritis caused by Streptococcus zooepidemicus is a rare event in humans. Of the four cases reported in the literature, only two patients had direct animal contact, and the portal of entry remained unclear in all cases. We report herein the case of a patient who suffered a purulent arthritis of the left shoulder caused by S. zooepidemicus, successfully treated in our department. A diagnostic FDG-PET-CT scan ruled out other foci of infection, but detected a hyperkeratotic plantar chronic soft tissue lesion of the left foot, acquired in a paragliding accident 10 years earlier. The fact that the patient habitually took care of his horses barefoot in boots, identifies the cutaneous portal of entry as most likely. To our knowledge this is the first report of a septic arthritis caused by S. zooepidemicus where a cutaneous entry route is described.

  3. Assessment and characterization of biofilm formation among human isolates of Streptococcus dysgalactiae subsp. equisimilis.

    PubMed

    Genteluci, Gabrielle Limeira; Silva, Ligia Guedes; Souza, Maria Clara; Glatthardt, Thaís; de Mattos, Marcos Corrêa; Ejzemberg, Regina; Alviano, Celuta Sales; Figueiredo, Agnes Marie Sá; Ferreira-Carvalho, Bernadete Teixeira

    2015-12-01

    The capacity to form biofilm is considered a protective mechanism that allows the bacteria to survive and proliferate in hostile environments, facilitating the maintenance of the infectious process. Recently, biofilm has become a topic of interest in the study of the human pathogen group A Streptococcus (GAS). Although GAS has not been associated with infection on medical implants, the presence of microcolonies embedded in an extracellular matrix on infected tissues has been reported. Despite the similarity between GAS and Streptococcus dysgalactiae subspecies equisimilis (SDSE), there are no studies in the literature describing the production of biofilm by SDSE. In this work, we assessed and characterized biofilm development among SDSE human isolates of group C. The in vitro data showed that 59.3% of the 118 isolates tested were able to form acid-induced biofilm on glass, and 28% formed it on polystyrene surfaces. More importantly, biofilm was also formed in a foreign body model in mice. The biofilm structure was analyzed by confocal laser scanning microscopy, transmission electron microscopy, and scanning electron microscopy. Long fibrillar-like structures were observed by scanning electron microscopy. Additionally, the expression of a pilus associated gene of SDSE was increased for in vitro sessile cells compared with planktonics, and when sessile cells were collected from biofilms formed in the animal model compared with that of in vitro model. Results obtained from the immunofluorescence microscopy indicated the biofilm was immunogenic. Our data also suggested a role for proteins, exopolysaccharide and extracellular DNA in the formation and accumulation of biofilm by SDSE.

  4. Immunomodulatory Properties of Streptococcus and Veillonella Isolates from the Human Small Intestine Microbiota

    PubMed Central

    Zoetendal, Erwin G.; Wells, Jerry M.; Kleerebezem, Michiel

    2014-01-01

    The human small intestine is a key site for interactions between the intestinal microbiota and the mucosal immune system. Here we investigated the immunomodulatory properties of representative species of commonly dominant small-intestinal microbial communities, including six streptococcal strains (four Streptococcus salivarius, one S. equinus, one S. parasanguinis) one Veillonella parvula strain, one Enterococcus gallinarum strain, and Lactobacillus plantarum WCFS1 as a bench mark strain on human monocyte-derived dendritic cells. The different streptococci induced varying levels of the cytokines IL-8, TNF-α, and IL-12p70, while the V. parvula strain showed a strong capacity to induce IL-6. E. gallinarum strain was a potent inducer of cytokines and TLR2/6 signalling. As Streptococcus and Veillonella can potentially interact metabolically and frequently co-occur in ecosystems, immunomodulation by pair-wise combinations of strains were also tested for their combined immunomodulatory properties. Strain combinations induced cytokine responses in dendritic cells that differed from what might be expected on the basis of the results obtained with the individual strains. A combination of (some) streptococci with Veillonella appeared to negate IL-12p70 production, while augmenting IL-8, IL-6, IL-10, and TNF-α responses. This suggests that immunomodulation data obtained in vitro with individual strains are unlikely to adequately represent immune responses to mixtures of gut microbiota communities in vivo. Nevertheless, analysing the immune responses of strains representing the dominant species in the intestine may help to identify immunomodulatory mechanisms that influence immune homeostasis. PMID:25479553

  5. Immunomodulatory Effects of Streptococcus suis Capsule Type on Human Dendritic Cell Responses, Phagocytosis and Intracellular Survival

    PubMed Central

    Meijerink, Marjolein; Ferrando, Maria Laura; Lammers, Geraldine; Taverne, Nico; Smith, Hilde E.; Wells, Jerry M.

    2012-01-01

    Streptococcus suis is a major porcine pathogen of significant commercial importance worldwide and an emerging zoonotic pathogen of humans. Given the important sentinel role of mucosal dendritic cells and their importance in induction of T cell responses we investigated the effect of different S. suis serotype strains and an isogenic capsule mutant of serotype 2 on the maturation, activation and expression of IL-10, IL-12p70 and TNF-α in human monocyte-derived dendritic cells. Additionally, we compared phagocytosis levels and bacterial survival after internalization. The capsule of serotype 2, the most common serotype associated with infection in humans and pigs, was highly anti-phagocytic and modulated the IL-10/IL-12 and IL-10/TNF-α cytokine production in favor of a more anti-inflammatory profile compared to other serotypes. This may have consequences for the induction of effective immunity to S. suis serotype 2 in humans. A shielding effect of the capsule on innate Toll-like receptor signaling was also demonstrated. Furthermore, we showed that 24 h after phagocytosis, significant numbers of viable intracellular S. suis were still present intracellularly. This may contribute to the dissemination of S. suis in the body. PMID:22558240

  6. Humoral Immunity to Commensal Oral Bacteria in Human Infants: Salivary Secretory Immunoglobulin A Antibodies Reactive with Streptococcus mitis biovar 1, Streptococcus oralis, Streptococcus mutans, and Enterococcus faecalis during the First Two Years of Life

    PubMed Central

    Cole, Michael F.; Bryan, Stacey; Evans, Mishell K.; Pearce, Cheryl L.; Sheridan, Michael J.; Sura, Patricia A.; Wientzen, Raoul L.; Bowden, George H. W.

    1999-01-01

    Secretory immunoglobulin A (SIgA) antibodies reactive with the pioneer oral streptococci Streptococcus mitis biovar 1 and Streptococcus oralis, the late oral colonizer Streptococcus mutans, and the pioneer enteric bacterium Enterococcus faecalis in saliva samples from 10 human infants from birth to age 2 years were analyzed. Low levels of salivary SIgA1 and SIgA2 antibodies reactive with whole cells of all four species were detected within the first month after birth, even though S. mutans and E. faecalis were not recovered from the mouths of the infants during the study period. Although there was a fivefold increase in the concentration of SIgA between birth and age 2 years, there were no differences between the concentrations of SIgA1 and SIgA2 antibodies reactive with the four species over this time period. When the concentrations of SIgA1 and SIgA2 antibodies reactive with all four species were normalized to the concentrations of SIgA1 and SIgA2 in saliva, SIgA1 and SIgA2 antibodies reactive with these bacteria showed a significant decrease from birth to 2 years of age. Adsorption of each infant’s saliva with cells of one species produced a dramatic reduction of antibodies recognizing the other three species. Sequential adsorption of saliva samples removed all SIgA antibody to the bacteria, indicating that the SIgA antibodies were directed to antigens shared by all four species. The induction by the host of a limited immune response to common antigens that are likely not involved in adherence may be among the mechanisms that commensal streptococci employ to persist in the oral cavity. PMID:10085031

  7. Genetic loci of Streptococcus mitis that mediate binding to human platelets.

    PubMed

    Bensing, B A; Rubens, C E; Sullam, P M

    2001-03-01

    The direct binding of bacteria to platelets is a postulated major interaction in the pathogenesis of infective endocarditis. To identify bacterial components that mediate platelet binding by Streptococcus mitis, we screened a Tn916deltaE-derived mutant library of S. mitis strain SF100 for reduced binding to human platelets in vitro. Two distinct loci were found to affect platelet binding. The first contains a gene (pblT) encoding a highly hydrophobic, 43-kDa protein with 12 potential membrane-spanning segments. This protein resembles members of the major facilitator superfamily of small-molecule transporters. The second platelet binding locus consists of an apparent polycistronic operon. This region includes genes that are highly similar to those of Lactococcus lactis phage r1t and Streptococcus thermophilus phage 01205. Two genes (pblA and pblB) encoding large surface proteins are also present. The former encodes a 107-kDa protein containing tryptophan-rich repeats, which may serve to anchor the protein within the cell wall. The latter encodes a 121-kDa protein most similar to a tail fiber protein from phage 01205. Functional mapping by insertion-duplication mutagenesis and gene complementation indicates that PblB may be a platelet adhesin and that expression of PblB may be linked to that of PblA. The combined data indicate that at least two genomic regions contribute to platelet binding by S. mitis. One encodes a probable transmembrane transporter, while the second encodes two large surface proteins resembling structural components of lysogenic phages.

  8. Species-specific interaction of Streptococcus pneumoniae with human complement factor H

    PubMed Central

    Lu, Ling; Ma, Zhuo; Jokiranta, T. Sakari; Whitney, Adeline R.; DeLeo, Frank R.; Zhang, Jing-Ren

    2008-01-01

    Streptococcus pneumoniae naturally colonizes the nasopharynx as a commensal organism and sometimes causes infections in remote tissue sites. This bacterium is highly capable of resisting host innate immunity during nasopharyngeal colonization and disseminating infections. The ability to recruit complement factor H (FH) by S. pneumoniae has been implicated as a bacterial immune evasion mechanism against complement-mediated bacterial clearance because FH is a complement alternative pathway inhibitor. S. pneumoniae recruits FH through a previously defined FH-binding domain of choline-binding protein A (CbpA), a major surface protein of S. pneumoniae. In this study, we show that CbpA binds to human FH but not to the FH proteins of mouse and other animal species tested thus far. Accordingly, deleting the FH-binding domain of CbpA in strain D39 did not result in obvious change in the levels of pneumococcal bacteremia or virulence in a bacteremia mouse model. Furthermore, this species-specific pneumococcal interaction with FH was shown to occur in multiple pneumococcal isolates from the blood and cerebrospinal fluid (CSF). Finally, our phagocytosis experiments with human- and mouse phagocytes and complement systems provide additional evidence to support our hypothesis that CbpA acts as a bacterial determinant for pneumococcal resistance to complement-mediated host defense in humans. PMID:18981135

  9. A hemolytic pigment of Group B Streptococcus allows bacterial penetration of human placenta.

    PubMed

    Whidbey, Christopher; Harrell, Maria Isabel; Burnside, Kellie; Ngo, Lisa; Becraft, Alexis K; Iyer, Lakshminarayan M; Aravind, L; Hitti, Jane; Waldorf, Kristina M Adams; Rajagopal, Lakshmi

    2013-06-01

    Microbial infection of the amniotic fluid is a significant cause of fetal injury, preterm birth, and newborn infections. Group B Streptococcus (GBS) is an important human bacterial pathogen associated with preterm birth, fetal injury, and neonatal mortality. Although GBS has been isolated from amniotic fluid of women in preterm labor, mechanisms of in utero infection remain unknown. Previous studies indicated that GBS are unable to invade human amniotic epithelial cells (hAECs), which represent the last barrier to the amniotic cavity and fetus. We show that GBS invades hAECs and strains lacking the hemolysin repressor CovR/S accelerate amniotic barrier failure and penetrate chorioamniotic membranes in a hemolysin-dependent manner. Clinical GBS isolates obtained from women in preterm labor are hyperhemolytic and some are associated with covR/S mutations. We demonstrate for the first time that hemolytic and cytolytic activity of GBS is due to the ornithine rhamnolipid pigment and not due to a pore-forming protein toxin. Our studies emphasize the importance of the hemolytic GBS pigment in ascending infection and fetal injury.

  10. A hemolytic pigment of Group B Streptococcus allows bacterial penetration of human placenta

    PubMed Central

    Whidbey, Christopher; Harrell, Maria Isabel; Burnside, Kellie; Ngo, Lisa; Becraft, Alexis K.; Iyer, Lakshminarayan M.; Aravind, L.; Hitti, Jane

    2013-01-01

    Microbial infection of the amniotic fluid is a significant cause of fetal injury, preterm birth, and newborn infections. Group B Streptococcus (GBS) is an important human bacterial pathogen associated with preterm birth, fetal injury, and neonatal mortality. Although GBS has been isolated from amniotic fluid of women in preterm labor, mechanisms of in utero infection remain unknown. Previous studies indicated that GBS are unable to invade human amniotic epithelial cells (hAECs), which represent the last barrier to the amniotic cavity and fetus. We show that GBS invades hAECs and strains lacking the hemolysin repressor CovR/S accelerate amniotic barrier failure and penetrate chorioamniotic membranes in a hemolysin-dependent manner. Clinical GBS isolates obtained from women in preterm labor are hyperhemolytic and some are associated with covR/S mutations. We demonstrate for the first time that hemolytic and cytolytic activity of GBS is due to the ornithine rhamnolipid pigment and not due to a pore-forming protein toxin. Our studies emphasize the importance of the hemolytic GBS pigment in ascending infection and fetal injury. PMID:23712433

  11. Intermedilysin, a novel cytotoxin specific for human cells secreted by Streptococcus intermedius UNS46 isolated from a human liver abscess.

    PubMed Central

    Nagamune, H; Ohnishi, C; Katsuura, A; Fushitani, K; Whiley, R A; Tsuji, A; Matsuda, Y

    1996-01-01

    A novel cytotoxin (intermedilysin) specific for human cells was identified as a cytolytic factor of Streptococcus intermedius UNS46 isolated from a human liver abscess. Intermedilysin caused human cell death with membrane blebs. Intermedilysin was purified from UNS46 culture medium by means of gel filtration and hydrophobic chromatography. The purified toxin was resolved into major and minor bands of 54 and 53 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These proteins reacted with an antibody against intermedilysin. Five internal peptide fragments of intermedilysin were sequenced and found to have 42 to 71% homology with the thiol-activated cytotoxin pneumolysin. However, the action of intermedilysin differed from that of thiol-activated cytotoxins, especially in terms of a lack of activation by dithiothreitol and resistance to treatments with N-ethylmaleimide and 5,5'-dithio-bis-(2-nitrobenzoic acid), although cholesterol inhibited the toxin activity. Intermedilysin was potently hemolytic on human erythrocytes but was 100-fold less effective on chimpanzee and cynomolgus monkey erythrocytes. Intermedilysin was not hemolytic in nine other animal species tested. Since human erythrocytes treated with trypsin were far less sensitive to intermedilysin than were the intact cells, a cell membrane protein(s) may participate in the intermedilysin action. These data demonstrated that intermedilysin is distinguishable from all known bacterial cytolysins. PMID:8757839

  12. A comprehensive analysis of the Streptococcus pyogenes and human plasma protein interaction network.

    PubMed

    Sjöholm, Kristoffer; Karlsson, Christofer; Linder, Adam; Malmström, Johan

    2014-07-01

    Streptococcus pyogenes is a major human bacterial pathogen responsible for severe and invasive disease associated with high mortality rates. The bacterium interacts with several human blood plasma proteins and clarifying these interactions and their biological consequences will help to explain the progression from mild to severe infections. In this study, we used a combination of mass spectrometry (MS) based techniques to comprehensively quantify the components of the S. pyogenes-plasma protein interaction network. From an initial list of 181 interacting human plasma proteins defined using liquid chromatography (LC)-MS/MS analysis we further subdivided the interacting protein list using selected reaction monitoring (SRM) depending on the level of enrichment and protein concentration on the bacterial surface. The combination of MS methods revealed several previously characterized interactions between the S. pyogenes surface and human plasma along with many more, so far uncharacterised, possible plasma protein interactions with S. pyogenes. In follow-up experiments, the combination of MS techniques was applied to study differences in protein binding to a S. pyogenes wild type strain and an isogenic mutant lacking several important virulence factors, and a unique pair of invasive and non-invasive S. pyogenes isolates from the same patient. Comparing the plasma protein-binding properties of the wild type and the mutant and the invasive and non-invasive S. pyogenes bacteria revealed considerable differences, underlining the significance of these protein interactions. The results also demonstrate the power of the developed mass spectrometry method to investigate host-microbial relationships with a large proteomics depth and high quantitative accuracy.

  13. IκBζ Regulates Human Monocyte Pro-Inflammatory Responses Induced by Streptococcus pneumoniae

    PubMed Central

    Sundaram, Kruthika; Rahman, Mohd. Akhlakur; Mitra, Srabani; Knoell, Daren L.; Woodiga, Shireen A.; King, Samantha J.

    2016-01-01

    Pneumococcal lung infections represent a major cause of death worldwide. Single nucleotide polymorphisms (SNPs) in the NFKBIZ gene, encoding the transcription factor IκBζ, are associated with increased susceptibility to invasive pneumococcal disease. We hence analyzed how IκBζ might regulate inflammatory responses to pneumococcal infection. We first demonstrate that IκBζ is expressed in human blood monocytes but not in bronchial epithelial cells, in response to wild type pneumococcal strain D39. D39 transiently induced IκBζ in a dose dependent manner, with subsequent induction of downstream molecules involved in host defense. Of these molecules, IκBζ knockdown reduced the expression of IL-6 and GMCSF. Furthermore, IκBζ overexpression increased the activity of IL-6 and GMCSF promoters, supporting the knockdown findings. Pneumococci lacking either pneumolysin or capsule still induced IκBζ. While inhibition of TLR1/TLR2 blocked D39 induced IκBζ expression, TLR4 inhibition did not. Blockade of p38 MAP kinase and NFκB suppressed D39 induced IκBζ. Overall, our data demonstrates that IκBζ regulates monocyte inflammatory responses to Streptococcus pneumoniae by promoting the production of IL-6 and GMCSF. PMID:27597997

  14. IκBζ Regulates Human Monocyte Pro-Inflammatory Responses Induced by Streptococcus pneumoniae.

    PubMed

    Sundaram, Kruthika; Rahman, Mohd Akhlakur; Mitra, Srabani; Knoell, Daren L; Woodiga, Shireen A; King, Samantha J; Wewers, Mark D

    2016-01-01

    Pneumococcal lung infections represent a major cause of death worldwide. Single nucleotide polymorphisms (SNPs) in the NFKBIZ gene, encoding the transcription factor IκBζ, are associated with increased susceptibility to invasive pneumococcal disease. We hence analyzed how IκBζ might regulate inflammatory responses to pneumococcal infection. We first demonstrate that IκBζ is expressed in human blood monocytes but not in bronchial epithelial cells, in response to wild type pneumococcal strain D39. D39 transiently induced IκBζ in a dose dependent manner, with subsequent induction of downstream molecules involved in host defense. Of these molecules, IκBζ knockdown reduced the expression of IL-6 and GMCSF. Furthermore, IκBζ overexpression increased the activity of IL-6 and GMCSF promoters, supporting the knockdown findings. Pneumococci lacking either pneumolysin or capsule still induced IκBζ. While inhibition of TLR1/TLR2 blocked D39 induced IκBζ expression, TLR4 inhibition did not. Blockade of p38 MAP kinase and NFκB suppressed D39 induced IκBζ. Overall, our data demonstrates that IκBζ regulates monocyte inflammatory responses to Streptococcus pneumoniae by promoting the production of IL-6 and GMCSF. PMID:27597997

  15. Co-Transcriptomes of Initial Interactions In Vitro between Streptococcus Pneumoniae and Human Pleural Mesothelial Cells.

    PubMed

    Heath, Claire J; del Mar Cendra, Maria; Watson, Alastair; Auger, Jean-Philippe; Pandey, Anish; Tighe, Paddy; Christodoulides, Myron

    2015-01-01

    Streptococcus pneumoniae (Spn) is a major causative organism of empyema, an inflammatory condition occurring in the pleural sac. In this study, we used human and Spn cDNA microarrays to characterize the transcriptional responses occurring during initial contact between Spn and a human pleural mesothelial cell line (PMC) in vitro. Using stringent filtering criteria, 42 and 23 Spn genes were up-and down-regulated respectively. In particular, genes encoding factors potentially involved in metabolic processes and Spn adherence to eukaryotic cells were up-regulated e.g. glnQ, glnA, aliA, psaB, lytB and nox. After Spn initial contact, 870 human genes were differentially regulated and the largest numbers of significant gene expression changes were found in canonical pathways for eukaryotic initiation factor 2 signaling (60 genes out of 171), oxidative phosphorylation (32/103), mitochondrial dysfunction (37/164), eIF4 and p70S6K signaling (28/142), mTOR signaling (27/182), NRF2-mediated oxidative stress response (20/177), epithelial adherens junction remodeling (11/66) and ubiquitination (22/254). The cellular response appeared to be directed towards host cell survival and defense. Spn did not activate NF-kB or phosphorylate p38 MAPK or induce cytokine production from PMC. Moreover, Spn infection of TNF-α pre-stimulated PMC inhibited production of IL-6 and IL-8 secretion by >50% (p<0.01). In summary, this descriptive study provides datasets and a platform for examining further the molecular mechanisms underlying the pathogenesis of empyema. PMID:26566142

  16. Co-Transcriptomes of Initial Interactions In Vitro between Streptococcus Pneumoniae and Human Pleural Mesothelial Cells

    PubMed Central

    Heath, Claire J.; del Mar Cendra, Maria; Watson, Alastair; Auger, Jean-Philippe; Pandey, Anish; Tighe, Paddy; Christodoulides, Myron

    2015-01-01

    Streptococcus pneumoniae (Spn) is a major causative organism of empyema, an inflammatory condition occurring in the pleural sac. In this study, we used human and Spn cDNA microarrays to characterize the transcriptional responses occurring during initial contact between Spn and a human pleural mesothelial cell line (PMC) in vitro. Using stringent filtering criteria, 42 and 23 Spn genes were up-and down-regulated respectively. In particular, genes encoding factors potentially involved in metabolic processes and Spn adherence to eukaryotic cells were up-regulated e.g. glnQ, glnA, aliA, psaB, lytB and nox. After Spn initial contact, 870 human genes were differentially regulated and the largest numbers of significant gene expression changes were found in canonical pathways for eukaryotic initiation factor 2 signaling (60 genes out of 171), oxidative phosphorylation (32/103), mitochondrial dysfunction (37/164), eIF4 and p70S6K signaling (28/142), mTOR signaling (27/182), NRF2-mediated oxidative stress response (20/177), epithelial adherens junction remodeling (11/66) and ubiquitination (22/254). The cellular response appeared to be directed towards host cell survival and defense. Spn did not activate NF-kB or phosphorylate p38 MAPK or induce cytokine production from PMC. Moreover, Spn infection of TNF-α pre-stimulated PMC inhibited production of IL-6 and IL-8 secretion by >50% (p<0.01). In summary, this descriptive study provides datasets and a platform for examining further the molecular mechanisms underlying the pathogenesis of empyema. PMID:26566142

  17. Population-Based Study of Streptococcus suis Infection in Humans in Phayao Province in Northern Thailand

    PubMed Central

    Takeuchi, Dan; Kerdsin, Anusak; Pienpringam, Anupong; Loetthong, Phacharaphan; Samerchea, Sutit; Luangsuk, Pakkinee; Khamisara, Kasean; Wongwan, Nithita; Areeratana, Prasanee; Chiranairadul, Piphat; Lertchayanti, Suwat; Petcharat, Sininat; Yowang, Amara; Chaiwongsaen, Phanupong; Nakayama, Tatsuya; Akeda, Yukihiro; Hamada, Shigeyuki; Sawanpanyalert, Pathom; Dejsirilert, Surang; Oishi, Kazunori

    2012-01-01

    Background Streptococcus suis infection in humans has received increasing worldwide recognition. Methods and Findings A prospective study of S. suis infection in humans was conducted in Phayao Province in northern Thailand to determine the incidence and the risk behaviors of the disease in this region in 2010. Thirty-one cases were confirmed. The case fatality rate was 16.1%, and the estimated incidence rate was 6.2 per 100,000 in the general population. The peak incidence occurred in May. The median age of the patients was 53 years and 64.5% were men. Consumption of raw pork products was confirmed in 22 cases and the median incubation period (range) was 2 days (0–11) after consumption of raw pork products. Isolates from 31 patients were confirmed as serotype 2 in 23 patients (74.2%) and serotype 14 in eight patients (25.8%). The major sequence types (STs) were ST1 (n = 20) for serotype 2 and ST105 (n = 8) for serotype 14. The epidemiological analysis suggested three possible clusters, which included 17 cases. In the largest possible cluster of 10 cases in Chiang Kham and its neighboring districts in May, the source of infection in four cases was identified as a raw pork dish served at the same restaurant in this district. Microbiological analysis confirmed that three of four cases associated with consumption of raw pork at this restaurant were attributable to an identical strain of serotype 2 with ST1 and pulsotype A2. Conclusions Our data suggest a high incidence rate of S. suis infection in the general population in Phayao Province in 2010 and confirm a cluster of three cases in 31 human cases. Food safety control should be strengthened especially for raw pork products in northern Thailand. PMID:22363601

  18. Genomic Evidence for the Evolution of Streptococcus equi: Host Restriction, Increased Virulence, and Genetic Exchange with Human Pathogens

    PubMed Central

    Paillot, Romain; Steward, Karen F.; Webb, Katy; Ainslie, Fern; Jourdan, Thibaud; Bason, Nathalie C.; Holroyd, Nancy E.; Mungall, Karen; Quail, Michael A.; Sanders, Mandy; Simmonds, Mark; Willey, David; Brooks, Karen; Aanensen, David M.; Spratt, Brian G.; Jolley, Keith A.; Maiden, Martin C. J.; Kehoe, Michael; Chanter, Neil; Bentley, Stephen D.; Robinson, Carl; Maskell, Duncan J.; Parkhill, Julian; Waller, Andrew S.

    2009-01-01

    The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered. Streptococcus equi subspecies equi (S. equi) is a host-restricted pathogen of horses that has evolved from the zoonotic pathogen Streptococcus equi subspecies zooepidemicus (S. zooepidemicus). These pathogens share approximately 80% genome sequence identity with the important human pathogen Streptococcus pyogenes. We sequenced and compared the genomes of S. equi 4047 and S. zooepidemicus H70 and screened S. equi and S. zooepidemicus strains from around the world to uncover evidence of the genetic events that have shaped the evolution of the S. equi genome and led to its emergence as a host-restricted pathogen. Our analysis provides evidence of functional loss due to mutation and deletion, coupled with pathogenic specialization through the acquisition of bacteriophage encoding a phospholipase A2 toxin, and four superantigens, and an integrative conjugative element carrying a novel iron acquisition system with similarity to the high pathogenicity island of Yersinia pestis. We also highlight that S. equi, S. zooepidemicus, and S. pyogenes share a common phage pool that enhances cross-species pathogen evolution. We conclude that the complex interplay of functional loss, pathogenic specialization, and genetic exchange between S. equi, S. zooepidemicus, and S. pyogenes continues to influence the evolution of these important streptococci. PMID:19325880

  19. Characterization of a Streptococcus suis tet(O/W/32/O)-carrying element transferable to major streptococcal pathogens.

    PubMed

    Palmieri, Claudio; Magi, Gloria; Mingoia, Marina; Bagnarelli, Patrizia; Ripa, Sandro; Varaldo, Pietro E; Facinelli, Bruna

    2012-09-01

    Mosaic tetracycline resistance determinants are a recently discovered class of hybrids of ribosomal protection tet genes. They may show different patterns of mosaicism, but their final size has remained unaltered. Initially thought to be confined to a small group of anaerobic bacteria, mosaic tet genes were then found to be widespread. In the genus Streptococcus, a mosaic tet gene [tet(O/W/32/O)] was first discovered in Streptococcus suis, an emerging drug-resistant pig and human pathogen. In this study, we report the molecular characterization of a tet(O/W/32/O) gene-carrying mobile element from an S. suis isolate. tet(O/W/32/O) was detected, in tandem with tet(40), in a circular 14,741-bp genetic element (39.1% G+C; 17 open reading frames [ORFs] identified). The novel element, which we designated 15K, also carried the macrolide resistance determinant erm(B) and an aminoglycoside resistance four-gene cluster including aadE (streptomycin) and aphA (kanamycin). 15K appeared to be an unstable genetic element that, in the absence of recombinases, is capable of undergoing spontaneous excision under standard growth conditions. In the integrated form, 15K was found inside a 54,879-bp integrative and conjugative element (ICE) (50.5% G+C; 55 ORFs), which we designated ICESsu32457. An ∼1.3-kb segment that apparently served as the att site for excision of the unstable 15K element was identified. The novel ICE was transferable at high frequency to recipients from pathogenic Streptococcus species (S. suis, Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus agalactiae), suggesting that the multiresistance 15K element can successfully spread within streptococcal populations.

  20. Streptococcus pneumoniae Enhances Human Respiratory Syncytial Virus Infection In Vitro and In Vivo

    PubMed Central

    Nguyen, D. Tien; Louwen, Rogier; Elberse, Karin; van Amerongen, Geert; Yüksel, Selma; Luijendijk, Ad; Osterhaus, Albert D. M. E.; Duprex, W. Paul; de Swart, Rik L.

    2015-01-01

    Human respiratory syncytial virus (HRSV) and Streptococcus pneumoniae are important causative agents of respiratory tract infections. Both pathogens are associated with seasonal disease outbreaks in the pediatric population, and can often be detected simultaneously in infants hospitalized with bronchiolitis or pneumonia. It has been described that respiratory virus infections may predispose for bacterial superinfections, resulting in severe disease. However, studies on the influence of bacterial colonization of the upper respiratory tract on the pathogenesis of subsequent respiratory virus infections are scarce. Here, we have investigated whether pneumococcal colonization enhances subsequent HRSV infection. We used a newly generated recombinant subgroup B HRSV strain that expresses enhanced green fluorescent protein and pneumococcal isolates obtained from healthy children in disease-relevant in vitro and in vivo model systems. Three pneumococcal strains specifically enhanced in vitro HRSV infection of primary well-differentiated normal human bronchial epithelial cells grown at air-liquid interface, whereas two other strains did not. Since previous studies reported that bacterial neuraminidase enhanced HRSV infection in vitro, we measured pneumococcal neuraminidase activity in these cultures but found no correlation with the observed infection enhancement in our model. Subsequently, a selection of pneumococcal strains was used to induce nasal colonization of cotton rats, the best available small animal model for HRSV. Intranasal HRSV infection three days later resulted in strain-specific enhancement of HRSV replication in vivo. One S. pneumoniae strain enhanced HRSV both in vitro and in vivo, and was also associated with enhanced syncytium formation in vivo. However, neither pneumococci nor HRSV were found to spread from the upper to the lower respiratory tract, and neither pathogen was transmitted to naive cage mates by direct contact. These results demonstrate

  1. Human Nasal Challenge with Streptococcus pneumoniae Is Immunising in the Absence of Carriage

    PubMed Central

    Gritzfeld, Jenna F.; Wright, Angela D.; Armitage, Kathryn; Jambo, Kondwani C.; Bate, Emily; El Batrawy, Sherouk; Collins, Andrea; Gordon, Stephen B.

    2012-01-01

    Infectious challenge of the human nasal mucosa elicits immune responses that determine the fate of the host-bacterial interaction; leading either to clearance, colonisation and/or disease. Persistent antigenic exposure from pneumococcal colonisation can induce both humoral and cellular defences that are protective against carriage and disease. We challenged healthy adults intra-nasally with live 23F or 6B Streptococcus pneumoniae in two sequential cohorts and collected nasal wash, bronchoalveolar lavage (BAL) and blood before and 6 weeks after challenge. We hypothesised that both cohorts would successfully become colonised but this did not occur except for one volunteer. The effect of bacterial challenge without colonisation in healthy adults has not been previously assessed. We measured the antigen-specific humoral and cellular immune responses in challenged but not colonised volunteers by ELISA and Flow Cytometry. Antigen-specific responses were seen in each compartment both before and after bacterial challenge for both cohorts. Antigen-specific IgG and IgA levels were significantly elevated in nasal wash 6 weeks after challenge compared to baseline. Immunoglobulin responses to pneumococci were directed towards various protein targets but not capsular polysaccharide. 23F but not 6B challenge elevated IgG anti-PspA in BAL. Serum immunoglobulins did not increase in response to challenge. In neither challenge cohort was there any alteration in the frequencies of TNF, IL-17 or IFNγ producing CD4 T cells before or after challenge in BAL or blood. We show that simple, low dose mucosal exposure with pneumococci may immunise mucosal surfaces by augmenting anti-protein immunoglobulin responses; but not capsular or cellular responses. We hypothesise that mucosal exposure alone may not replicate the systemic immunising effect of experimental or natural carriage in humans. PMID:22496648

  2. Intracellular Streptococcus pyogenes in Human Macrophages Display an Altered Gene Expression Profile

    PubMed Central

    Hertzén, Erika; Johansson, Linda; Kansal, Rita; Hecht, Alexander; Dahesh, Samira; Janos, Marton; Nizet, Victor; Kotb, Malak; Norrby-Teglund, Anna

    2012-01-01

    Streptococcus pyogenes is an important human pathogen, which has recently gained recognition as an intracellular microorganism during the course of severe invasive infections such as necrotizing fasciitis. Although the surface anchored M protein has been identified as a pivotal factor affecting phagosomal maturation and S. pyogenes survival within macrophages, the overall transcriptional profile required for the pathogen to adapt and persist intracellularly is as of yet unknown. To address this, the gene expression profile of S. pyogenes within human macrophages was determined and compared to that of extracellular bacteria using customized microarrays and real-time qRT-PCR. In order to model the early phase of infection involving adaptation to the intracellular compartment, samples were collected 2h post-infection. Microarray analysis revealed that the expression of 145 streptococcal genes was significantly altered in the intracellular environment. The majority of differentially regulated genes were associated with metabolic and energy-dependent processes. Key up-regulated genes in early phase intracellular bacteria were ihk and irr, encoding a two-component gene regulatory system (TCS). Comparison of gene expression of selected genes at 2h and 6h post-infection revealed a dramatic shift in response regulators over time with a down-regulation of ihk/irr genes concurring with an up-regulation of the covR/S TCS. In re-infection assays, intracellular bacteria from the 6h time point exhibited significantly greater survival within macrophages than did bacteria collected at the 2h time point. An isogenic S. pyogenes mutant deficient in ihk/irr displayed significantly reduced bacterial counts when compared to wild-type bacteria following infection of macrophages. The findings illustrate how gene expression of S. pyogenes during the intracellular life cycle is fine-tuned by temporal expression of specific two-component systems. PMID:22511985

  3. Intracellular Streptococcus pyogenes in human macrophages display an altered gene expression profile.

    PubMed

    Hertzén, Erika; Johansson, Linda; Kansal, Rita; Hecht, Alexander; Dahesh, Samira; Janos, Marton; Nizet, Victor; Kotb, Malak; Norrby-Teglund, Anna

    2012-01-01

    Streptococcus pyogenes is an important human pathogen, which has recently gained recognition as an intracellular microorganism during the course of severe invasive infections such as necrotizing fasciitis. Although the surface anchored M protein has been identified as a pivotal factor affecting phagosomal maturation and S. pyogenes survival within macrophages, the overall transcriptional profile required for the pathogen to adapt and persist intracellularly is as of yet unknown. To address this, the gene expression profile of S. pyogenes within human macrophages was determined and compared to that of extracellular bacteria using customized microarrays and real-time qRT-PCR. In order to model the early phase of infection involving adaptation to the intracellular compartment, samples were collected 2h post-infection. Microarray analysis revealed that the expression of 145 streptococcal genes was significantly altered in the intracellular environment. The majority of differentially regulated genes were associated with metabolic and energy-dependent processes. Key up-regulated genes in early phase intracellular bacteria were ihk and irr, encoding a two-component gene regulatory system (TCS). Comparison of gene expression of selected genes at 2h and 6h post-infection revealed a dramatic shift in response regulators over time with a down-regulation of ihk/irr genes concurring with an up-regulation of the covR/S TCS. In re-infection assays, intracellular bacteria from the 6h time point exhibited significantly greater survival within macrophages than did bacteria collected at the 2h time point. An isogenic S. pyogenes mutant deficient in ihk/irr displayed significantly reduced bacterial counts when compared to wild-type bacteria following infection of macrophages. The findings illustrate how gene expression of S. pyogenes during the intracellular life cycle is fine-tuned by temporal expression of specific two-component systems.

  4. Genome-wide identification of genes essential for the survival of Streptococcus pneumoniae in human saliva.

    PubMed

    Verhagen, Lilly M; de Jonge, Marien I; Burghout, Peter; Schraa, Kiki; Spagnuolo, Lorenza; Mennens, Svenja; Eleveld, Marc J; van der Gaast-de Jongh, Christa E; Zomer, Aldert; Hermans, Peter W M; Bootsma, Hester J

    2014-01-01

    Since Streptococcus pneumoniae transmits through droplet spread, this respiratory tract pathogen may be able to survive in saliva. Here, we show that saliva supports survival of clinically relevant S. pneumoniae strains for more than 24 h in a capsule-independent manner. Moreover, saliva induced growth of S. pneumoniae in growth-permissive conditions, suggesting that S. pneumoniae is well adapted for uptake of nutrients from this bodily fluid. By using Tn-seq, a method for genome-wide negative selection screening, we identified 147 genes potentially required for growth and survival of S. pneumoniae in saliva, among which genes predicted to be involved in cell envelope biosynthesis, cell transport, amino acid metabolism, and stress response predominated. The Tn-seq findings were validated by testing a panel of directed gene deletion mutants for their ability to survive in saliva under two testing conditions: at room temperature without CO2, representing transmission, and at 37 °C with CO2, representing in-host carriage. These validation experiments confirmed that the plsX gene and the amiACDEF and aroDEBC operons, involved in respectively fatty acid metabolism, oligopeptide transport, and biosynthesis of aromatic amino acids play an important role in the growth and survival of S. pneumoniae in saliva at 37 °C. In conclusion, this study shows that S. pneumoniae is well-adapted for growth and survival in human saliva and provides a genome-wide list of genes potentially involved in adaptation. This notion supports earlier evidence that S. pneumoniae can use human saliva as a vector for transmission.

  5. Commensal Streptococcus salivarius Modulates PPARγ Transcriptional Activity in Human Intestinal Epithelial Cells

    PubMed Central

    Couvigny, Benoît; de Wouters, Tomas; Kaci, Ghalia; Jacouton, Elsa; Delorme, Christine; Doré, Joël; Renault, Pierre; Blottière, Hervé M.

    2015-01-01

    The impact of commensal bacteria in eukaryotic transcriptional regulation has increasingly been demonstrated over the last decades. A multitude of studies have shown direct effects of commensal bacteria from local transcriptional activity to systemic impact. The commensal bacterium Streptococcus salivarius is one of the early bacteria colonizing the oral and gut mucosal surfaces. It has been shown to down-regulate nuclear transcription factor (NF-кB) in human intestinal cells, a central regulator of the host mucosal immune system response to the microbiota. In order to evaluate its impact on a further important transcription factor shown to link metabolism and inflammation in the intestine, namely PPARγ (peroxisome proliferator-activated receptor), we used human intestinal epithelial cell-lines engineered to monitor PPARγ transcriptional activity in response to a wide range of S. salivarius strains. We demonstrated that different strains from this bacterial group share the property to inhibit PPARγ activation independently of the ligand used. First attempts to identify the nature of the active compounds showed that it is a low-molecular-weight, DNase-, proteases- and heat-resistant metabolite secreted by S. salivarius strains. Among PPARγ-targeted metabolic genes, I-FABP and Angptl4 expression levels were dramatically reduced in intestinal epithelial cells exposed to S. salivarius supernatant. Both gene products modulate lipid accumulation in cells and down-regulating their expression might consequently affect host health. Our study shows that species belonging to the salivarius group of streptococci impact both host inflammatory and metabolic regulation suggesting a possible role in the host homeostasis and health. PMID:25946041

  6. Commensal Streptococcus salivarius Modulates PPARγ Transcriptional Activity in Human Intestinal Epithelial Cells.

    PubMed

    Couvigny, Benoît; de Wouters, Tomas; Kaci, Ghalia; Jacouton, Elsa; Delorme, Christine; Doré, Joël; Renault, Pierre; Blottière, Hervé M; Guédon, Eric; Lapaque, Nicolas

    2015-01-01

    The impact of commensal bacteria in eukaryotic transcriptional regulation has increasingly been demonstrated over the last decades. A multitude of studies have shown direct effects of commensal bacteria from local transcriptional activity to systemic impact. The commensal bacterium Streptococcus salivarius is one of the early bacteria colonizing the oral and gut mucosal surfaces. It has been shown to down-regulate nuclear transcription factor (NF-кB) in human intestinal cells, a central regulator of the host mucosal immune system response to the microbiota. In order to evaluate its impact on a further important transcription factor shown to link metabolism and inflammation in the intestine, namely PPARγ (peroxisome proliferator-activated receptor), we used human intestinal epithelial cell-lines engineered to monitor PPARγ transcriptional activity in response to a wide range of S. salivarius strains. We demonstrated that different strains from this bacterial group share the property to inhibit PPARγ activation independently of the ligand used. First attempts to identify the nature of the active compounds showed that it is a low-molecular-weight, DNase-, proteases- and heat-resistant metabolite secreted by S. salivarius strains. Among PPARγ-targeted metabolic genes, I-FABP and Angptl4 expression levels were dramatically reduced in intestinal epithelial cells exposed to S. salivarius supernatant. Both gene products modulate lipid accumulation in cells and down-regulating their expression might consequently affect host health. Our study shows that species belonging to the salivarius group of streptococci impact both host inflammatory and metabolic regulation suggesting a possible role in the host homeostasis and health. PMID:25946041

  7. Genome-Wide Identification of Genes Required for Fitness of Group A Streptococcus in Human Blood

    PubMed Central

    Le Breton, Yoann; Mistry, Pragnesh; Valdes, Kayla M.; Quigley, Jeffrey; Kumar, Nikhil; Tettelin, Hervé

    2013-01-01

    The group A streptococcus (GAS) is a strict human pathogen responsible for a wide spectrum of diseases. Although GAS genome sequences are available, functional genomic analyses have been limited. We developed a mariner-based transposon, osKaR, designed to perform Transposon-Site Hybridization (TraSH) in GAS and successfully tested its use in several invasive serotypes. A complex osKaR mutant library in M1T1 GAS strain 5448 was subjected to negative selection in human blood to identify genes important for GAS fitness in this clinically relevant environment. Mutants underrepresented after growth in blood (output pool) compared to growth in rich media (input pool) were identified using DNA microarray hybridization of transposon-specific tags en masse. Using blood from three different donors, we identified 81 genes that met our criteria for reduced fitness in blood from at least two individuals. Genes known to play a role in survival of GAS in blood were found, including those encoding the virulence regulator Mga (mga), the peroxide response regulator PerR (perR), and the RofA-like regulator Ralp-3 (ralp3). We also identified genes previously reported for their contribution to sepsis in other pathogens, such as de novo nucleotide synthesis (purD, purA, pyrB, carA, carB, guaB), sugar metabolism (scrB, fruA), zinc uptake (adcC), and transcriptional regulation (cpsY). To validate our findings, independent mutants with mutations in 10 different genes identified in our screen were confirmed to be defective for survival in blood bactericidal assays. Overall, this work represents the first use of TraSH in GAS to identify potential virulence genes. PMID:23297387

  8. Liamocin oil from Aureobasidium pullulans has antibacterial activity with specificity for species of Streptococcus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Liamocin oil from Aureobasidium pullulans NRRL 50380 was tested for antibacterial activity. Liamocins inhibited growth of Streptococcus agalactiae, S. uberis, S. mitis, S. infantarius, and S. mutans, with minimum inhibitory concentrations from 20 'g/ml to 78 'g/ml. Enterococcus faecalis was less sus...

  9. 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

  10. Characterization of the duodenase-1 gene and its associations with resistance to Streptococuus agalactiae in hybrid tilapia (Oreochromis spp.).

    PubMed

    Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

    2015-08-01

    Tilapia is a group of cultured teleost fishes whose production is threatened by some diseases. Identification of DNA markers associated with disease resistance in candidate genes may facilitate to accelerate the selection of disease resistance. The gene encoding a duodenase, which can trigger immune response, has not been studied in fish. We characterized the cDNA of duodenase-1 gene of hybrid tilapia. Its ORF is 759 bp, encoding a serine protease of 252 amino acids. This gene consisted of five exons and four introns. Its expression was detected in all 10 tissues examined, and it was highly expressed in the intestine and kidney. After a challenge with the bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the intestine, liver and spleen. We identified seven SNPs in the gene and found that four of them were significantly associated with the resistance to S. agalactiae (P < 0.05). The CGTCC haplotype, CAGTC/CGGTC and CGTCC/CGTCC diplotype were significantly associated with the resistance to S. agalactiae (P = 0.00, 0.04 and < 0.0001, respectively). In addition, one SNP was associated significantly with growth traits (P < 0.05). These findings suggest that the duodenase-1 gene plays an important role in the resistance to S. agalactiae in tilapia. The SNP markers in the duodenase-1 gene associated with resistance to the bacterial pathogen, may facilitate the selection of tilapia resistant to the bacterial disease. PMID:26052009

  11. Response of Fatty Acid Synthesis Genes to the Binding of Human Salivary Amylase by Streptococcus gordonii

    PubMed Central

    Nikitkova, Anna E.; Haase, Elaine M.; Vickerman, M. Margaret; Gill, Steven R.

    2012-01-01

    Streptococcus gordonii, an important primary colonizer of dental plaque biofilm, specifically binds to salivary amylase via the surface-associated amylase-binding protein A (AbpA). We hypothesized that a function of amylase binding to S. gordonii may be to modulate the expression of chromosomal genes, which could influence bacterial survival and persistence in the oral cavity. Gene expression profiling by microarray analysis was performed to detect genes in S. gordonii strain CH1 that were differentially expressed in response to the binding of purified human salivary amylase versus exposure to purified heat-denatured amylase. Selected genes found to be differentially expressed were validated by quantitative reverse transcription-PCR (qRT-PCR). Five genes from the fatty acid synthesis (FAS) cluster were highly (10- to 35-fold) upregulated in S. gordonii CH1 cells treated with native amylase relative to those treated with denatured amylase. An abpA-deficient strain of S. gordonii exposed to amylase failed to show a response in FAS gene expression similar to that observed in the parental strain. Predicted phenotypic effects of amylase binding to S. gordonii strain CH1 (associated with increased expression of FAS genes, leading to changes in fatty acid synthesis) were noted; these included increased bacterial growth, survival at low pH, and resistance to triclosan. These changes were not observed in the amylase-exposed abpA-deficient strain, suggesting a role for AbpA in the amylase-induced phenotype. These results provide evidence that the binding of salivary amylase elicits a differential gene response in S. gordonii, resulting in a phenotypic adjustment that is potentially advantageous for bacterial survival in the oral environment. PMID:22247133

  12. Bacteriophage lysin mediates the binding of streptococcus mitis to human platelets through interaction with fibrinogen.

    PubMed

    Seo, Ho Seong; Xiong, Yan Q; Mitchell, Jennifer; Seepersaud, Ravin; Bayer, Arnold S; Sullam, Paul M

    2010-01-01

    The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. We have previously found that platelet binding by Streptococcus mitis SF100 is mediated by surface components encoded by a lysogenic bacteriophage, SM1. We now demonstrate that SM1-encoded lysin contributes to platelet binding via its direct interaction with fibrinogen. Far Western blotting of platelets revealed that fibrinogen was the major membrane-associated protein bound by lysin. Analysis of lysin binding with purified fibrinogen in vitro confirmed that these proteins could bind directly, and that this interaction was both saturable and inhibitable. Lysin bound both the Aalpha and Bbeta chains of fibrinogen, but not the gamma subunit. Binding of lysin to the Bbeta chain was further localized to a region within the fibrinogen D fragment. Disruption of the SF100 lysin gene resulted in an 83+/-3.1% reduction (mean +/- SD) in binding to immobilized fibrinogen by this mutant strain (PS1006). Preincubation of this isogenic mutant with purified lysin restored fibrinogen binding to wild type levels. When tested in a co-infection model of endocarditis, loss of lysin expression resulted in a significant reduction in virulence, as measured by achievable bacterial densities (CFU/g) within vegetations, kidneys, and spleens. These results indicate that bacteriophage-encoded lysin is a multifunctional protein, representing a new class of fibrinogen-binding proteins. Lysin appears to be cell wall-associated through its interaction with choline. Once on the bacterial surface, lysin can bind fibrinogen directly, which appears to be an important interaction for the pathogenesis of endocarditis. PMID:20714354

  13. Interaction of pneumolysin-sufficient and -deficient isogenic variants of Streptococcus pneumoniae with human respiratory mucosa.

    PubMed Central

    Rayner, C F; Jackson, A D; Rutman, A; Dewar, A; Mitchell, T J; Andrew, P W; Cole, P J; Wilson, R

    1995-01-01

    Streptococcus pneumoniae is the most common cause of community-acquired pneumonia, and pneumolysin, a hemolytic toxin, is thought to be an important virulence factor. We have studied the interaction of a pneumolysin-sufficient type II S. pneumoniae strain (PL+) and an otherwise identical pneumolysin-deficient derivative (PL-) with human respiratory mucosa in an organ culture with an air interface for up to 48 h. Ciliary beat frequency (CBF) was measured by a photometric technique, and adherence to and invasion of the epithelium were assessed by scanning and transmission electron microscopy. PL+ and PL- caused a progressive fall in CBF compared with the control which became significant (P < 0.01) at 24 h for PL+ and at 48 h for PL-. At 24 h, there was a significant increase in the percentage of the mucosa of the organ culture that was damaged for PL+ compared with the control (P < 0.01) and PL- (P < 0.02). At 48 h, there was a significant increase in mucosal damage for both PL+ (P < 0.005) and PL- (P < 0.05) compared with the control. At 24 and 48 h, PL+ and PL- adhered predominantly to mucus and damaged cells. PL+ infection alone caused separation of tight junctions between epithelial cells, and at 48 h PL+ cells were adherent to the separated edges of otherwise healthy unciliated cells. PL+ and PL- both caused damage to the epithelial cell ultrastructure. S. pneumoniae infection caused patchy damage to the respiratory mucosa and a lowered CBF. These changes were more severe and occurred earlier with the pneumolysin-sufficient variant. PMID:7822008

  14. Bacteriophage lysin mediates the binding of streptococcus mitis to human platelets through interaction with fibrinogen.

    PubMed

    Seo, Ho Seong; Xiong, Yan Q; Mitchell, Jennifer; Seepersaud, Ravin; Bayer, Arnold S; Sullam, Paul M

    2010-08-12

    The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. We have previously found that platelet binding by Streptococcus mitis SF100 is mediated by surface components encoded by a lysogenic bacteriophage, SM1. We now demonstrate that SM1-encoded lysin contributes to platelet binding via its direct interaction with fibrinogen. Far Western blotting of platelets revealed that fibrinogen was the major membrane-associated protein bound by lysin. Analysis of lysin binding with purified fibrinogen in vitro confirmed that these proteins could bind directly, and that this interaction was both saturable and inhibitable. Lysin bound both the Aalpha and Bbeta chains of fibrinogen, but not the gamma subunit. Binding of lysin to the Bbeta chain was further localized to a region within the fibrinogen D fragment. Disruption of the SF100 lysin gene resulted in an 83+/-3.1% reduction (mean +/- SD) in binding to immobilized fibrinogen by this mutant strain (PS1006). Preincubation of this isogenic mutant with purified lysin restored fibrinogen binding to wild type levels. When tested in a co-infection model of endocarditis, loss of lysin expression resulted in a significant reduction in virulence, as measured by achievable bacterial densities (CFU/g) within vegetations, kidneys, and spleens. These results indicate that bacteriophage-encoded lysin is a multifunctional protein, representing a new class of fibrinogen-binding proteins. Lysin appears to be cell wall-associated through its interaction with choline. Once on the bacterial surface, lysin can bind fibrinogen directly, which appears to be an important interaction for the pathogenesis of endocarditis.

  15. Bacteriophage Lysin Mediates the Binding of Streptococcus mitis to Human Platelets through Interaction with Fibrinogen

    PubMed Central

    Seo, Ho Seong; Xiong, Yan Q.; Mitchell, Jennifer; Seepersaud, Ravin; Bayer, Arnold S.; Sullam, Paul M.

    2010-01-01

    The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. We have previously found that platelet binding by Streptococcus mitis SF100 is mediated by surface components encoded by a lysogenic bacteriophage, SM1. We now demonstrate that SM1-encoded lysin contributes to platelet binding via its direct interaction with fibrinogen. Far Western blotting of platelets revealed that fibrinogen was the major membrane-associated protein bound by lysin. Analysis of lysin binding with purified fibrinogen in vitro confirmed that these proteins could bind directly, and that this interaction was both saturable and inhibitable. Lysin bound both the Aα and Bβ chains of fibrinogen, but not the γ subunit. Binding of lysin to the Bβ chain was further localized to a region within the fibrinogen D fragment. Disruption of the SF100 lysin gene resulted in an 83±3.1% reduction (mean ± SD) in binding to immobilized fibrinogen by this mutant strain (PS1006). Preincubation of this isogenic mutant with purified lysin restored fibrinogen binding to wild type levels. When tested in a co-infection model of endocarditis, loss of lysin expression resulted in a significant reduction in virulence, as measured by achievable bacterial densities (CFU/g) within vegetations, kidneys, and spleens. These results indicate that bacteriophage-encoded lysin is a multifunctional protein, representing a new class of fibrinogen-binding proteins. Lysin appears to be cell wall-associated through its interaction with choline. Once on the bacterial surface, lysin can bind fibrinogen directly, which appears to be an important interaction for the pathogenesis of endocarditis. PMID:20714354

  16. Streptococcus dysgalactiae subsp. equisimilis Isolated From Infections in Dogs and Humans: Are Current Subspecies Identification Criteria accurate?

    PubMed

    Ciszewski, Marcin; Zegarski, Kamil; Szewczyk, Eligia M

    2016-11-01

    Streptococcus dysgalactiae is a pyogenic species pathogenic both for humans and animals. Until recently, it has been considered an exclusive animal pathogen causing infections in wild as well as domestic animals. Currently, human infections are being reported with increasing frequency, and their clinical picture is often similar to the ones caused by Streptococcus pyogenes. Due to the fact that S. dysgalactiae is a heterogeneous species, it was divided into two subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD). The first differentiation criterion, described in 1996, was based on strain isolation source. Currently applied criteria, published in 1998, are based on hemolysis type and Lancefield group classification. In this study, we compared subspecies identification results for 36 strains isolated from clinical cases both in humans and animals. Species differentiation was based on two previously described criteria as well as MALDI-TOF and genetic analyses: RISA and 16S rRNA genes sequencing. Antimicrobial susceptibility profiles were also determined according to CLSI guidelines. The results presented in our study suggest that the subspecies differentiation criteria previously described in the above two literature positions seem to be inaccurate in analyzed group of strains, the hemolysis type on blood agar, and Lancefield classification should not be here longer considered as criteria in subspecies identification. The antimicrobial susceptibility tests indicate emerging of multiresistant human SDSE strains resistant also to vancomycin, linezolid and tigecycline, which might pose a substantial problem in treatment. PMID:27502064

  17. Genomic analysis reveals the molecular basis for capsule loss in the group B Streptococcus population.

    PubMed

    Rosini, Roberto; Campisi, Edmondo; De Chiara, Matteo; Tettelin, Hervé; Rinaudo, Daniela; Toniolo, Chiara; Metruccio, Matteo; Guidotti, Silvia; Sørensen, Uffe B Skov; Kilian, Mogens; Ramirez, Mario; Janulczyk, Robert; Donati, Claudio; Grandi, Guido; Margarit, Immaculada

    2015-01-01

    The human and bovine bacterial pathogen Streptococcus agalactiae (Group B Streptococcus, GBS) expresses a thick polysaccharide capsule that constitutes a major virulence factor and vaccine target. GBS can be classified into ten distinct serotypes differing in the chemical composition of their capsular polysaccharide. However, non-typeable strains that do not react with anti-capsular sera are frequently isolated from colonized and infected humans and cattle. To gain a comprehensive insight into the molecular basis for the loss of capsule expression in GBS, a collection of well-characterized non-typeable strains was investigated by genome sequencing. Genome based phylogenetic analysis extended to a wide population of sequenced strains confirmed the recently observed high clonality among GBS lineages mainly containing human strains, and revealed a much higher degree of diversity in the bovine population. Remarkably, non-typeable strains were equally distributed in all lineages. A number of distinct mutations in the cps operon were identified that were apparently responsible for inactivation of capsule synthesis. The most frequent genetic alterations were point mutations leading to stop codons in the cps genes, and the main target was found to be cpsE encoding the portal glycosyl transferase of capsule biosynthesis. Complementation of strains carrying missense mutations in cpsE with a wild-type gene restored capsule expression allowing the identification of amino acid residues essential for enzyme activity.

  18. Genomic Analysis Reveals the Molecular Basis for Capsule Loss in the Group B Streptococcus Population

    PubMed Central

    Rosini, Roberto; Campisi, Edmondo; De Chiara, Matteo; Tettelin, Hervé; Rinaudo, Daniela; Toniolo, Chiara; Metruccio, Matteo; Guidotti, Silvia; Sørensen, Uffe B. Skov; Kilian, Mogens; Ramirez, Mario; Janulczyk, Robert; Donati, Claudio; Grandi, Guido; Margarit, Immaculada

    2015-01-01

    The human and bovine bacterial pathogen Streptococcus agalactiae (Group B Streptococcus, GBS) expresses a thick polysaccharide capsule that constitutes a major virulence factor and vaccine target. GBS can be classified into ten distinct serotypes differing in the chemical composition of their capsular polysaccharide. However, non-typeable strains that do not react with anti-capsular sera are frequently isolated from colonized and infected humans and cattle. To gain a comprehensive insight into the molecular basis for the loss of capsule expression in GBS, a collection of well-characterized non-typeable strains was investigated by genome sequencing. Genome based phylogenetic analysis extended to a wide population of sequenced strains confirmed the recently observed high clonality among GBS lineages mainly containing human strains, and revealed a much higher degree of diversity in the bovine population. Remarkably, non-typeable strains were equally distributed in all lineages. A number of distinct mutations in the cps operon were identified that were apparently responsible for inactivation of capsule synthesis. The most frequent genetic alterations were point mutations leading to stop codons in the cps genes, and the main target was found to be cpsE encoding the portal glycosyl trasferase of capsule biosynthesis. Complementation of strains carrying missense mutations in cpsE with a wild-type gene restored capsule expression allowing the identification of amino acid residues essential for enzyme activity. PMID:25946017

  19. Genomic analysis reveals the molecular basis for capsule loss in the group B Streptococcus population.

    PubMed

    Rosini, Roberto; Campisi, Edmondo; De Chiara, Matteo; Tettelin, Hervé; Rinaudo, Daniela; Toniolo, Chiara; Metruccio, Matteo; Guidotti, Silvia; Sørensen, Uffe B Skov; Kilian, Mogens; Ramirez, Mario; Janulczyk, Robert; Donati, Claudio; Grandi, Guido; Margarit, Immaculada

    2015-01-01

    The human and bovine bacterial pathogen Streptococcus agalactiae (Group B Streptococcus, GBS) expresses a thick polysaccharide capsule that constitutes a major virulence factor and vaccine target. GBS can be classified into ten distinct serotypes differing in the chemical composition of their capsular polysaccharide. However, non-typeable strains that do not react with anti-capsular sera are frequently isolated from colonized and infected humans and cattle. To gain a comprehensive insight into the molecular basis for the loss of capsule expression in GBS, a collection of well-characterized non-typeable strains was investigated by genome sequencing. Genome based phylogenetic analysis extended to a wide population of sequenced strains confirmed the recently observed high clonality among GBS lineages mainly containing human strains, and revealed a much higher degree of diversity in the bovine population. Remarkably, non-typeable strains were equally distributed in all lineages. A number of distinct mutations in the cps operon were identified that were apparently responsible for inactivation of capsule synthesis. The most frequent genetic alterations were point mutations leading to stop codons in the cps genes, and the main target was found to be cpsE encoding the portal glycosyl transferase of capsule biosynthesis. Complementation of strains carrying missense mutations in cpsE with a wild-type gene restored capsule expression allowing the identification of amino acid residues essential for enzyme activity. PMID:25946017

  20. Host and Bacterial Phenotype Variation in Adhesion of Streptococcus mutans to Matched Human Hosts

    PubMed Central

    Esberg, Anders; Löfgren-Burström, Anna; Öhman, Ulla

    2012-01-01

    The commensal pathogen Streptococcus mutans uses AgI/II adhesins to adhere to gp340 adsorbed on teeth. Here we analyzed isolates of S. mutans (n = 70 isolates) from caries and caries-free human extremes (n = 19 subjects) by multilocus sequence typing (MLST), AgI/II full-length gene sequencing, and adhesion to parotid saliva matched from the strain donors (nested from a case-control sample of defined gp340 and acidic proline-rich protein [PRP] profiles). The concatenated MLST as well as AgI/II gene sequences showed unique sequence types between, and identical types within, the subjects. The matched adhesion levels ranged widely (40% adhesion range), from low to moderate to high, between subjects but were similar within subjects (or sequence types). In contrast, the adhesion avidity of the strains was narrow, normally distributed for high, moderate, or low adhesion reference saliva or pure gp340 regardless of the sequence type. The adhesion of S. mutans Ingbritt and matched isolates and saliva samples correlated (r = 0.929), suggesting that the host specify about four-fifths (r2 = 0.86) of the variation in matched adhesion. Half of the variation in S. mutans Ingbritt adhesion to saliva from the caries cases-controls (n = 218) was explained by the primary gp340 receptor and PRP coreceptor composition. The isolates also varied, although less so, in adhesion to standardized saliva (18% adhesion range) and clustered into three major AgI/II groups (groups A, B1, and B2) due to two variable V-region segments and diverse AgI/II sequence types due to a set of single-amino-acid substitutions. Isolates with AgI/II type A versus types B1 and B2 tended to differ in gp340 binding avidity and qualitative adhesion profiles for saliva gp340 phenotypes. In conclusion, the host saliva phenotype plays a more prominent role in S. mutans adhesion than anticipated previously. PMID:22927045

  1. Immunochemistry of the Streptococcus mutans BHT cell membrane: detection of determinants cross-reactive with human heart tissue.

    PubMed Central

    Ayakawa, G Y; Siegel, J L; Crowley, P J; Bleiweis, A S

    1985-01-01

    Cell membranes of Streptococcus mutans BHT serotype b were prepared after glass bead disruption or mutanolysin digestion of whole cells. Immunoblot analyses of BHT membrane extracts revealed major polypeptides of 42,000, 46,000, 62,000, and 82,000 daltons, as well as several minor bands, to be reactive with rabbit anti-human heart immunoglobulins. Heart cross-reactive antigens have been reported in the cell walls and culture fluids of several S. mutans serotypes. This represents the first report of cell membrane-localized heart cross-reactive antigens in this oral pathogen. Positive enzyme-linked immunosorbent assay and immunoblot reactions were also obtained with heart tissue antigen and anti-BHT sera, indicating mutual cross-reactivity. The major cross-reactive component detected by immunoblotting of human heart extracts was a 69,000-dalton polypeptide. Images PMID:3886543

  2. Validation of an Immunodiagnostic Assay for Detection of 13 Streptococcus pneumoniae Serotype-Specific Polysaccharides in Human Urine

    PubMed Central

    Huijts, Susanne M.; Wu, Kangjian; Souza, Victor; Passador, Sherry; Tinder, Chunyan; Song, Esther; Elfassy, Arik; McNeil, Lisa; Menton, Ronald; French, Roger; Callahan, Janice; Webber, Chris; Gruber, William C.; Bonten, Marc J. M.; Jansen, Kathrin U.

    2012-01-01

    To improve the clinical diagnosis of pneumococcal infection in bacteremic and nonbacteremic community-acquired pneumonia (CAP), a Luminex technology-based multiplex urinary antigen detection (UAD) diagnostic assay was developed and validated. The UAD assay can simultaneously detect 13 different serotypes of Streptococcus pneumoniae by capturing serotype-specific S. pneumoniae polysaccharides (PnPSs) secreted in human urine. Assay specificity is achieved by capturing the polysaccharides with serotype-specific monoclonal antibodies (MAbs) on spectrally unique microspheres. Positivity for each serotype was based on positivity cutoff values calculated from a standard curve run on each assay plate together with positive- and negative-control urine samples. The assay is highly specific, since significant signals are detected only when each PnPS was paired with its homologous MAb-coated microspheres. Validation experiments demonstrated excellent accuracy and precision. The UAD assay and corresponding positivity cutoff values were clinically validated by assessing 776 urine specimens obtained from patients with X-ray-confirmed CAP. The UAD assay demonstrated 97% sensitivity and 100% specificity using samples obtained from patients with bacteremic, blood culture-positive CAP. Importantly, the UAD assay identified Streptococcus pneumoniae (13 serotypes) in a proportion of individuals with nonbacteremic CAP, a patient population for which the pneumococcal etiology of CAP was previously difficult to assess. Therefore, the UAD assay provides a specific, noninvasive, sensitive, and reproducible tool to support vaccine efficacy as well as epidemiological evaluation of pneumococcal disease, including CAP, in adults. PMID:22675155

  3. Comparison of Citrated Human Blood, Citrated Sheep Blood, and Defibrinated Sheep Blood Mueller-Hinton Agar Preparations for Antimicrobial Susceptibility Testing of Streptococcus pneumoniae Isolates ▿

    PubMed Central

    Satzke, Catherine; Seduadua, Anna; Chandra, Reginald; Carapetis, Jonathan R.; Mulholland, E. Kim; Russell, Fiona M.

    2010-01-01

    The use of Mueller-Hinton agar supplemented with citrated human or citrated sheep blood was compared with the use of routinely used Mueller-Hinton agar supplemented with defibrinated sheep blood for antimicrobial susceptibility testing of Streptococcus pneumoniae. The alternate supplements were found to be unsatisfactory, particularly for testing resistant isolates, and therefore are not recommended. PMID:20668133

  4. Comparison of citrated human blood, citrated sheep blood, and defibrinated sheep blood Mueller-Hinton agar preparations for antimicrobial susceptibility testing of Streptococcus pneumoniae isolates.

    PubMed

    Satzke, Catherine; Seduadua, Anna; Chandra, Reginald; Carapetis, Jonathan R; Mulholland, E Kim; Russell, Fiona M

    2010-10-01

    The use of Mueller-Hinton agar supplemented with citrated human or citrated sheep blood was compared with the use of routinely used Mueller-Hinton agar supplemented with defibrinated sheep blood for antimicrobial susceptibility testing of Streptococcus pneumoniae. The alternate supplements were found to be unsatisfactory, particularly for testing resistant isolates, and therefore are not recommended.

  5. The surface protein HvgA mediates group B streptococcus hypervirulence and meningeal tropism in neonates

    PubMed Central

    Tazi, Asmaa; Disson, Olivier; Bellais, Samuel; Bouaboud, Abdelouhab; Dmytruk, Nicolas; Dramsi, Shaynoor; Mistou, Michel-Yves; Khun, Huot; Mechler, Charlotte; Tardieux, Isabelle; Trieu-Cuot, Patrick

    2010-01-01

    Streptococcus agalactiae (group B streptococcus; GBS) is a normal constituent of the intestinal microflora and the major cause of human neonatal meningitis. A single clone, GBS ST-17, is strongly associated with a deadly form of the infection called late-onset disease (LOD), which is characterized by meningitis in infants after the first week of life. The pathophysiology of LOD remains poorly understood, but our epidemiological and histopathological results point to an oral route of infection. Here, we identify a novel ST-17–specific surface-anchored protein that we call hypervirulent GBS adhesin (HvgA), and demonstrate that its expression is required for GBS hypervirulence. GBS strains that express HvgA adhered more efficiently to intestinal epithelial cells, choroid plexus epithelial cells, and microvascular endothelial cells that constitute the blood–brain barrier (BBB), than did strains that do not express HvgA. Heterologous expression of HvgA in nonadhesive bacteria conferred the ability to adhere to intestinal barrier and BBB-constituting cells. In orally inoculated mice, HvgA was required for intestinal colonization and translocation across the intestinal barrier and the BBB, leading to meningitis. In conclusion, HvgA is a critical virulence trait of GBS in the neonatal context and stands as a promising target for the development of novel diagnostic and antibacterial strategies. PMID:20956545

  6. Oral implantation in humans of Streptococcus mutans strains with different degrees of hydrophobicity.

    PubMed Central

    Svanberg, M; Westergren, G; Olsson, J

    1984-01-01

    The more hydrophobic, rough-colony-forming, streptomycin-resistant Streptococcus mutans parent strains GW Smr and LK Smr and the less hydrophobic, smooth-colony-forming, streptomycin-resistant variant strains GW36 Smr and LK36 Smr were implanted in oral cavities. Strains GW Smr and LK Smr implanted significantly better than strains GW36 Smr and LK36 Smr. The hydrophobicity of and the colony morphology formed by the different S. mutans strains did not seem to be affected throughout the experiment. PMID:6698609

  7. Dynamin inhibition interferes with inflammasome activation and cytokine gene expression in Streptococcus pyogenes-infected human macrophages

    PubMed Central

    Latvala, S; Mäkelä, S M; Miettinen, M; Charpentier, E; Julkunen, I

    2014-01-01

    In the present study, we have analysed the ability of Streptococcus pyogenes [Group A streptococcus (GAS)] to activate the NACHT-domain-, leucine-rich repeat- and PYD-containing protein 3 (NALP3) inflammasome complex in human monocyte-derived macrophages and the molecules and signalling pathways involved in GAS-induced inflammatory responses. We focused upon analysing the impact of dynamin-dependent endocytosis and the role of major streptococcal virulence factors streptolysin O (SLO) and streptolysin S (SLS) in the immune responses induced by GAS. These virulence factors are involved in immune evasion by forming pores in host cell membranes, and aid the bacteria to escape from the endosome–lysosome pathway. We analysed cytokine gene expression in human primary macrophages after stimulation with live or inactivated wild-type GAS as well as with live SLO and SLS defective bacteria. Interleukin (IL)-1β, IL-10, tumour necrosis factor (TNF)-α and chemokine (C-X-C motif) ligand (CXCL)-10 cytokines were produced after bacterial stimulation in a dose-dependent manner and no differences in cytokine levels were seen between live, inactivated or mutant bacteria. These data suggest that streptolysins or other secreted bacterial products are not required for the inflammatory responses induced by GAS. Our data indicate that inhibition of dynamin-dependent endocytosis in macrophages attenuates the induction of IL-1β, TNF-α, interferon (IFN)-β and CXCL-10 mRNAs. We also observed that pro-IL-1β protein was expressed and efficiently cleaved into mature-IL-1β via inflammasome activation after bacterial stimulation. Furthermore, we demonstrate that multiple signalling pathways are involved in GAS-stimulated inflammatory responses in human macrophages. PMID:25079511

  8. Capsule expression in Streptococcus mitis modulates interaction with oral keratinocytes and alters susceptibility to human antimicrobial peptides.

    PubMed

    Rukke, H V; Engen, S A; Schenck, K; Petersen, F C

    2016-08-01

    Streptococcus mitis is a colonizer of the oral cavity and the nasopharynx, and is closely related to Streptococcus pneumoniae. Both species occur in encapsulated and unencapsulated forms, but in S. mitis the role of the capsule in host interactions is mostly unknown. Therefore, the aim of this study was to examine how capsule expression in S. mitis can modulate interactions with the host with relevance for colonization. The S. mitis type strain, as well as two mutants of the type strain, an isogenic capsule deletion mutant, and a capsule switch mutant expressing the serotype 4 capsule of S. pneumoniae TIGR4, were used. Wild-type and capsule deletion strains of S. pneumoniae TIGR4 were included for comparison. We found that capsule production in S. mitis reduced adhesion to oral and lung epithelial cells. Further, exposure of oral epithelial cells to encapsulated S. mitis resulted in higher interleukin-6 and CXCL-8 transcription levels relative to the unencapsulated mutant. Capsule expression in S. mitis increased the sensitivity to human neutrophil peptide 1-3 but reduced the sensitivity to human β-defensin-3 and cathelicidin. This was in contrast with S. pneumoniae in which capsule expression has been generally associated with increased sensitivity to human antimicrobial peptides (AMPs). Collectively, these findings indicate that capsule expression in S. mitis is important in modulating interactions with epithelial cells, and is associated with increased or reduced susceptibility to AMPs depending on the nature of the AMP.

  9. 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

  10. Conserved patterns hidden within group A Streptococcus M protein hypervariability recognize human C4b-binding protein.

    PubMed

    Buffalo, Cosmo Z; Bahn-Suh, Adrian J; Hirakis, Sophia P; Biswas, Tapan; Amaro, Rommie E; Nizet, Victor; Ghosh, Partho

    2016-01-01

    No vaccine exists against group A Streptococcus (GAS), a leading cause of worldwide morbidity and mortality. A severe hurdle is the hypervariability of its major antigen, the M protein, with >200 different M types known. Neutralizing antibodies typically recognize M protein hypervariable regions (HVRs) and confer narrow protection. In stark contrast, human C4b-binding protein (C4BP), which is recruited to the GAS surface to block phagocytic killing, interacts with a remarkably large number of M protein HVRs (apparently ∼90%). Such broad recognition is rare, and we discovered a unique mechanism for this through the structure determination of four sequence-diverse M proteins in complexes with C4BP. The structures revealed a uniform and tolerant 'reading head' in C4BP, which detected conserved sequence patterns hidden within hypervariability. Our results open up possibilities for rational therapies that target the M-C4BP interaction, and also inform a path towards vaccine design. PMID:27595425

  11. Identifying protective Streptococcus pyogenes vaccine antigens recognized by both B and T cells in human adults and children

    PubMed Central

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine; Rosenkrands, Ida; Christensen, Jan Pravsgaard; Andersen, Peter; Dietrich, Jes

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well-conserved among different GAS strains, upregulated in host-pathogen interaction studies, and predicted to be extracellular or associated with the surface of the bacteria. The antigens were tested for both antibody recognition and T cell responses in human adults and children. The antigenicity of a selected group of antigens was further validated using a high-density peptide array technology that also identified the linear epitopes. Based on immunological recognition, four targets were selected and tested for protective capabilities in an experimental GAS infection model in mice. Shown for the first time, three of these targets (spy0469, spy1228 and spy1801) conferred significant protection whereas one (spy1643) did not. PMID:26911649

  12. Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources.

    PubMed

    Gherardi, Giovanni; Imperi, Monica; Palmieri, Claudio; Magi, Gloria; Facinelli, Bruna; Baldassarri, Lucilla; Pataracchia, Marco; Creti, Roberta

    2014-01-01

    A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS). A collection of 54 SDSE strains isolated in Italy in the years 2000-2010 from different sources (paediatric throat carriage, invasive and non-invasive diseases) was characterized by emm typing and pulsed-field gel electrophoresis (PFGE) analysis. The virulence repertoire was evaluated by PCR for the presence of GAS superantigen (spe) genes, the streptolysin S (sagA) gene, the group G fibronectin-binding protein (gfbA) gene and GAS-GBS alpha-like protein family (alp) genes; moreover, the ability to invade human epithelial cells was investigated. Resistance to tetracycline, erythromycin and clindamycin was assessed. The combined use of emm typing and PFGE proved to be a reliable strategy for the epidemiological analysis of SDSE isolates. The most frequent emm types were the same as those more frequently reported in other studies, thus indicating the diffusion of a limited number of a few successful emm types fit to disseminate in humans. The speG gene was detected in SDSE strains of different genetic backgrounds. Erythromycin resistance determined by the erm(T) gene, and the unusual, foggy MLSB phenotype, observed in one and seven strains, respectively, have never previously, to our knowledge, been reported in SDSE. Moreover, a new member of the alp family was identified. The identification of new antibiotic and virulence determinants, despite the small size of the sample analysed, shows the importance of constant attention to monitoring the extent of lateral gene transfer in this emerging pathogen.

  13. Genome-wide protective response used by group A Streptococcus to evade destruction by human polymorphonuclear leukocytes.

    PubMed

    Voyich, Jovanka M; Sturdevant, Daniel E; Braughton, Kevin R; Kobayashi, Scott D; Lei, Benfang; Virtaneva, Kimmo; Dorward, David W; Musser, James M; DeLeo, Frank R

    2003-02-18

    Group A Streptococcus (GAS) evades polymorphonuclear leukocyte (PMN) phagocytosis and killing to cause human disease, including pharyngitis and necrotizing fasciitis (flesh-eating syndrome). We show that GAS genes differentially regulated during phagocytic interaction with human PMNs comprise a global pathogen-protective response to innate immunity. GAS prophage genes and genes involved in virulence, oxidative stress, cell wall biosynthesis, and gene regulation were up-regulated during PMN phagocytosis. Genes encoding novel secreted proteins were up-regulated, and the proteins were produced during human GAS infections. We discovered an essential role for the Ihk-Irr two-component regulatory system in evading PMN-mediated killing and promoting host-cell lysis, processes that would facilitate GAS pathogenesis. Importantly, the irr gene was highly expressed during human GAS pharyngitis. We conclude that a complex pathogen genetic program circumvents human innate immunity to promote disease. The gene regulatory program revealed by our studies identifies previously undescribed potential vaccine antigens and targets for therapeutic interventions designed to control GAS infections.

  14. Binding of Streptococcus mutans SR protein to human monocytes: production of tumor necrosis factor, interleukin 1, and interleukin 6.

    PubMed

    Soell, M; Holveck, F; Schöller, M; Wachsmann, R D; Klein, J P

    1994-05-01

    To examine the possible implication of protein SR, an I/II-related antigen from Streptococcus mutans OMZ 175 (serotype f), in inflammatory reactions, we tested the immunomodulatory effects of protein SR on human monocytes. Using biotinylated protein, we provide evidence that protein SR binds to human monocytes in dose-, time-, and calcium-dependent manners through specific interactions. These results were confirmed by competition experiments using either soluble human monocyte extract or anti-SR immunoglobulin G. Binding occurred through lectin-like interactions between SR and carbohydrate portions of monocyte membrane glycoproteins, since binding could be inhibited by several sugars, especially fucose and N-acetylneuraminic acid (NANA), which were confirmed by ligand blotting to be the primer ligands recognized by SR on human monocyte extracts. The ability of protein SR to stimulate the production of cytokines by human circulating monocytes was then examined. The release of tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta, and interleukin 6 is time and dose dependent and not affected by the addition of polymyxin B. Activation of monocytes resulted from specific binding of SR to NANA and fucose present on cell surface glycoproteins since TNF-alpha release could be inhibited by sialidase and pronase treatment of monocytes and by NANA and fucose. These results confirm that sialic acid and fucose present on cell surface macromolecules and especially glycoproteins are needed for the binding of SR to monocytes and for the release of TNF-alpha. PMID:8168943

  15. Binding of Streptococcus mutans SR protein to human monocytes: production of tumor necrosis factor, interleukin 1, and interleukin 6.

    PubMed Central

    Soell, M; Holveck, F; Schöller, M; Wachsmann, R D; Klein, J P

    1994-01-01

    To examine the possible implication of protein SR, an I/II-related antigen from Streptococcus mutans OMZ 175 (serotype f), in inflammatory reactions, we tested the immunomodulatory effects of protein SR on human monocytes. Using biotinylated protein, we provide evidence that protein SR binds to human monocytes in dose-, time-, and calcium-dependent manners through specific interactions. These results were confirmed by competition experiments using either soluble human monocyte extract or anti-SR immunoglobulin G. Binding occurred through lectin-like interactions between SR and carbohydrate portions of monocyte membrane glycoproteins, since binding could be inhibited by several sugars, especially fucose and N-acetylneuraminic acid (NANA), which were confirmed by ligand blotting to be the primer ligands recognized by SR on human monocyte extracts. The ability of protein SR to stimulate the production of cytokines by human circulating monocytes was then examined. The release of tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta, and interleukin 6 is time and dose dependent and not affected by the addition of polymyxin B. Activation of monocytes resulted from specific binding of SR to NANA and fucose present on cell surface glycoproteins since TNF-alpha release could be inhibited by sialidase and pronase treatment of monocytes and by NANA and fucose. These results confirm that sialic acid and fucose present on cell surface macromolecules and especially glycoproteins are needed for the binding of SR to monocytes and for the release of TNF-alpha. Images PMID:8168943

  16. Entry of Sanfetrinem into Human Polymorphonuclear Granulocytes and Its Cell-Associated Activity against Intracellular, Penicillin-Resistant Streptococcus pneumoniae

    PubMed Central

    Cuffini, Anna Maria; Tullio, Vivian; Bonino, Alessandro; Allocco, Alessandra; Palarchio, Angela Ianni; Carlone, Nicola A.

    1998-01-01

    The entry of antibiotics into phagocytes is necessary for activity against intracellular pathogens. The ability of sanfetrinem, the first member of a new class of antibiotics, to penetrate human polymorphonuclear granulocytes and its consequences upon subsequent phagocytosis and killing of ingested penicillin-resistant Streptococcus pneumoniae have been evaluated. Sanfetrinem penetrated into human polymorphonuclear leukocytes (PMNs) at all concentrations tested, with cellular concentration/extracellular concentration ratios of 6.6 to 5.03 and 4.21 when sanfetrinem was used at 0.25 to 0.5 and 1 μg/ml, respectively, within 30 min of incubation. The uptake was complete within 5 min and was not energy dependent, since it was not affected by cell viability, environmental temperature, or the addition of a metabolic inhibitor. At a concentration of one-half the MIC, sanfetrinem significantly enhanced human PMN phagocytosis and increased intracellular bactericidal activity against penicillin-resistant S. pneumoniae. Following preexposure of PMNs to a concentration of one-half the MIC of sanfetrinem, there was a significant increase in both phagocytosis and killing compared with that for the controls, indicating the ability of sanfetrinem to interact with biological membranes and remain active within PMNs. Preexposure of streptococci to sanfetrinem made penicillin-resistant S. pneumoniae more susceptible to the bactericidal mechanisms of human PMNs than untreated organisms. PMID:9661015

  17. Human case of bacteremia due to Streptococcus suis serotype 5 in Japan: The first report and literature review.

    PubMed

    Taniyama, Daisuke; Sakurai, Mayu; Sakai, Tetsuya; Kikuchi, Takahide; Takahashi, Takashi

    2016-01-01

    Streptococcus suis is a zoonotic pathogen that can be transferred from pigs to humans. The serotypes 2 and 14 are prevalent among patients with S. suis infections, while other serotypes (i.e., 1, 4, 5, 16, and 24) have been detected in rare human cases. To the best of our knowledge, the present patient handling with raw pork is the first human case of uncomplicated bacteremia due to S. suis serotype 5 in Japan. We confirmed the new sequence type 752 of this isolate. Virulence-associated gene profiling was performed; both sly (encoding the hemolysin suilysin) and mrp (encoding a muramidase-released protein) were detected without amplification of epf (encoding the extracellular factor). Our polymerase chain reaction-based results indicated that this isolate possessed both tet(O), the tetracycline-resistance determinant, and erm(B), the macrolide/lincosamide-resistance determinant. In addition, we provide the review of literature concerning clinical and microbiological features of four human cases of infection due to S. suis serotype 5. Clinicians should be aware of this microorganism when examining and treating patients with fever, who are handling raw pork or having close contact with infected pigs even if they are immunocompetent. PMID:27689023

  18. Twitching motility and possession of polar fimbriae in spreading Streptococcus sanguis isolates from the human throat.

    PubMed

    Henriksen, S D; Henrichsen, J

    1975-04-01

    A collection of 19 strains of alpha haemolytic streptococci, isolated from throat swabs and characterized by production of spreading zones around colonies on blood agar, was found to constitute a very homogeneous group with morphological, physiological and biochemical characters corresponding to those of streptococci of ser-group H, or Streptococcus sanguis, and they all appeared to possess the group H antigen. They all had a common agglutinogen and, in addition, heterogeneous agglutinogens. The spreading growth, which appears to be a common property of S. sanguis, was due to twitching motility, and the spreading cultures possessed polar fimbriae. tneither twitching motility nor the possession of polar fimbriae have been observed in gram-positive bacteria before. PMID:1171576

  19. Transduction of the Streptococcus pyogenes bacteriophage Φm46.1, carrying resistance genes mef(A) and tet(O), to other Streptococcus species.

    PubMed

    Giovanetti, Eleonora; Brenciani, Andrea; Morroni, Gianluca; Tiberi, Erika; Pasquaroli, Sonia; Mingoia, Marina; Varaldo, Pietro E

    2014-01-01

    Φm46.1 - Streptococcus pyogenes bacteriophage carrying mef(A) and tet(O), respectively, encoding resistance to macrolides (M phenotype) and tetracycline - is widespread in S. pyogenes but has not been reported outside this species. Φm46.1 is transferable in vitro among S. pyogenes isolates, but no information is available about its transferability to other Streptococcus species. We thus investigated Φm46.1 for its ability to be transduced in vitro to recipients of different Streptococcus species. Transductants were obtained from recipients of Streptococcus agalactiae, Streptococcus gordonii, and Streptococcus suis. Retransfer was always achieved, and from S. suis to S. pyogenes occurred at a much greater frequency than in the opposite direction. In transductants Φm46.1 retained its functional properties, such as inducibility with mitomycin C, presence both as a prophage and as a free circular form, and transferability. The transductants shared the same Φm46.1 chromosomal integration site as the donor, at the 3' end of a conserved RNA uracil methyltransferase (rum) gene, which is an integration hotspot for a variety of genetic elements. No transfer occurred to recipients of Streptococcus pneumoniae, Streptococcus oralis, and Streptococcus salivarius, even though rum-like genes were also detected in the sequenced genomes of these species. A largely overlapping 18-bp critical sequence, where the site-specific recombination process presumably takes place, was identified in the rum genes of all recipients, including those of the species yielding no transductants. Growth assays to evaluate the fitness cost of Φm46.1 acquisition disclosed a negligible impact on S. pyogenes, S. agalactiae, and S. gordonii transductants and a noticeable fitness advantage in S. suis. The S. suis transductant also displayed marked overexpression of the autolysin-encoding gene atl.

  20. Epidemiological aspects of group B streptococci of bovine and human origin.

    PubMed Central

    Jensen, N. E.; Aarestrup, F. M.

    1996-01-01

    Restriction fragment length polymorphism of the gene encoding rRNA (ribotyping) was used in combination with conventional epidemiological markers to study phenotypic variations among Streptococcus agalactiae of bovine origin and the possible epidemiological interrelationship between the bovine and human reservoirs of Streptococcus agalactiae. The bovine material constituted 53 strains (9 antigen combinations) isolated from 11 herds. Herds with a uniform as well as heterogenic antigenic pattern were included. Furthermore, strains isolated in the course of time from the same persistently infected quarters were examined. The human material constituted 16 strains, 4 each of 4 serotypes, isolated from healthy carriers. Finally, nine serotype- and the group reference strains were examined. All strains were serotyped by double diffusion in agarose gel, biotyped (lactose +/-), and ribotyped using two restriction enzymes, Hind III and HhaI. All isolates could be typed by ribotyping and seven ribotypes were identified among the reference strains. The restriction enzymes used alone or in combination gave typing results that allowed discrimination between and within serotype. Combined use of serotype, Hind III and HhaI ribotypes produced 11 types among the 16 human strains. Ribotype analysis discriminated between herds infected with the same serotype. Strains of varying antigenic patterns from the same herd had the same ribotype. Phenotypic variations in serotype observed in persistent intramammary infection were not related to genetic changes as monitored by ribotype. Two ribotypes were represented among both bovine and human strains. The discriminating capability of lactose fermentation was of limited value. Images Fig. 1 Fig. 2 PMID:8972664

  1. Streptococcus pneumoniae Senses a Human-like Sialic Acid Profile via the Response Regulator CiaR.

    PubMed

    Hentrich, Karina; Löfling, Jonas; Pathak, Anuj; Nizet, Victor; Varki, Ajit; Henriques-Normark, Birgitta

    2016-09-14

    Streptococcus pneumoniae is a human-adapted pathogen that encounters terminally sialylated glycoconjugates and free sialic acid (Sia) in the airways. Upon scavenging by the bacterial sialidase NanA, Sias serve as carbon sources for the bacteria. Unlike most animals in which cytidine-monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) converts Sia N-acetylneuraminic acid (Neu5Ac) into N-glycolylneuraminic acid (Neu5Gc), humans have an inactive CMAH, causing an absence of Neu5Gc and excess Neu5Ac. We find that pneumococcal challenge in Cmah(-/-) mice leads to heightened bacterial loads, virulence, and NanA expression. In vitro, NanA is upregulated in response to Neu5Ac compared with Neu5Gc, a process controlled by the two-component response regulator CiaR and requiring Sia uptake by the transporter SatABC. Additionally, compared with Neu5Gc, Neu5Ac increases pneumococcal resistance to antimicrobial reactive oxygen species in a CiaR-dependent manner. Thus, S. pneumoniae senses and responds to Neu5Ac, leading to CiaR activation and increased virulence and potentially explaining the greater susceptibility in humans. PMID:27593514

  2. Mycoplasma agalactiae, an Etiological Agent of Contagious Agalactia in Small Ruminants: A Review

    PubMed Central

    Kumar, Amit; Rahal, Anu; Verma, Amit Kumar

    2014-01-01

    Mycoplasma agalactiae is one of the causal agents of classical contagious agalactia (CA), a serious, economically important but neglected enzootic disease of small ruminants. It occurs in many parts of the world and most notably in the Mediterranean Basin. Following the infection common complications are septicaemia, mastitis, arthritis, pleurisy, pneumonia, and keratoconjunctivitis. Primary or tentative diagnosis of the organism is based upon clinical signs. Various serological tests, namely, growth precipitation, immunofluorescence, complement fixation test, haemagglutination inhibition, agglutination, immunodiffusion, enzyme immunoassays, immunoelectrophoresis, blotting techniques, and others, are available. Molecular tools seem to be much more sensitive, specific, and faster and help to differentiate various strains. The real-time PCR, multiplex PCR, quantitative PCR, PCR-RFLP, MLST, and gene probes, complementary to segments of chromosomal DNA or 16S ribosomal RNA (rRNA), have strengthened the diagnosis of M. agalactiae. Both live attenuated and adjuvant (alum precipitated or saponified) inactivated vaccines are available with greater use of inactivated ones due to lack of side effects. The present review discusses the etiology, epidemiology, pathogenesis, and clinical signs of contagious agalactia in small ruminants along with trends and advances in its diagnosis, treatment, vaccination, prevention, and control strategies that will help in countering this disease. PMID:25097796

  3. BibA: a novel immunogenic bacterial adhesin contributing to group B Streptococcus survival in human blood.

    PubMed

    Santi, Isabella; Scarselli, Maria; Mariani, Massimo; Pezzicoli, Alfredo; Masignani, Vega; Taddei, Annarita; Grandi, Guido; Telford, John L; Soriani, Marco

    2007-02-01

    By the analysis of the recently sequenced genomes of Group B Streptococcus (GBS) we have identified a novel immunogenic adhesin with anti-phagocytic activity, named BibA. The bibA gene is present in 100% of the 24 GBS strains analysed. BibA-specific IgG were found in human sera from normal healthy donors. The putative protein product is a polypeptide of 630 amino acids containing a helix-rich N-terminal domain, a proline-rich region and a canonical LPXTG cell wall-anchoring domain. BibA is expressed on the surface of several GBS strains, but is also recovered in GBS culture supernatants. BibA specifically binds to human C4-binding protein, a regulator of the classic complement pathway. Deletion of the bibA gene severely reduced the capacity of GBS to survive in human blood and to resist opsonophagocytic killing by human neutrophils. In addition, BibA expression increased the virulence of GBS in a mouse infection model. The role of BibA in GBS adhesion was demonstrated by the impaired ability of a bibA knockout mutant strain to adhere to both human cervical and lung epithelial cells. Furthermore, we calculated that recombinant BibA bound to human epithelial cells of distinct origin with an affinity constant of approximately 10(-8) M for cervical epithelial cells. Hence BibA is a novel multifunctional protein involved in both resistance to phagocytic killing and adhesion to host cells. The identification of this potential new virulence factor represents an important step in the development of strategies to combat GBS-associated infections.

  4. 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

  5. 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

  6. Recolonization of human tooth surfaces by Streptococcus mutans after suppression by chlorhexidine treatment.

    PubMed

    Emilson, C G; Lindquist, B; Wennerholm, K

    1987-09-01

    In eight subjects who were initially highly colonized with Streptococcus mutans and who used a 1% chlorhexidine gel, the numbers of this organism were suppressed in both plaque and saliva. Bacterial plaque samples were obtained from all tooth surfaces, and the recolonization pattern of S. mutans was studied over a 26-week period. At baseline, 83% of all surfaces harbored S. mutans with buccal surfaces colonized in higher frequency than the others. After chlorhexidine treatment, the proportion of tooth surfaces colonized by S. mutans was reduced to a low level. Re-appearance was slow. S. mutans was first recovered from the most posterior teeth in the mouth, the molar surfaces were recolonized earlier than were those of pre-molars and anterior teeth, and the buccal surfaces were recolonized more readily than were the other tooth surfaces. The data show that there is a specific recolonization pattern of S. mutans after chlorhexidine treatment, and that the re-emergence of S. mutans is most probably due to regrowth of bacteria which have not been eradicated.

  7. 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

  8. Bacterial superantigens promote acute nasopharyngeal infection by Streptococcus pyogenes in a human MHC Class II-dependent manner.

    PubMed

    Kasper, Katherine J; Zeppa, Joseph J; Wakabayashi, Adrienne T; Xu, Stacey X; Mazzuca, Delfina M; Welch, Ian; Baroja, Miren L; Kotb, Malak; Cairns, Ewa; Cleary, P Patrick; Haeryfar, S M Mansour; McCormick, John K

    2014-05-01

    Establishing the genetic determinants of niche adaptation by microbial pathogens to specific hosts is important for the management and control of infectious disease. Streptococcus pyogenes is a globally prominent human-specific bacterial pathogen that secretes superantigens (SAgs) as 'trademark' virulence factors. SAgs function to force the activation of T lymphocytes through direct binding to lateral surfaces of T cell receptors and class II major histocompatibility complex (MHC-II) molecules. S. pyogenes invariably encodes multiple SAgs, often within putative mobile genetic elements, and although SAgs are documented virulence factors for diseases such as scarlet fever and the streptococcal toxic shock syndrome (STSS), how these exotoxins contribute to the fitness and evolution of S. pyogenes is unknown. Here we show that acute infection in the nasopharynx is dependent upon both bacterial SAgs and host MHC-II molecules. S. pyogenes was rapidly cleared from the nasal cavity of wild-type C57BL/6 (B6) mice, whereas infection was enhanced up to ∼10,000-fold in B6 mice that express human MHC-II. This phenotype required the SpeA superantigen, and vaccination with an MHC -II binding mutant toxoid of SpeA dramatically inhibited infection. Our findings indicate that streptococcal SAgs are critical for the establishment of nasopharyngeal infection, thus providing an explanation as to why S. pyogenes produces these potent toxins. This work also highlights that SAg redundancy exists to avoid host anti-SAg humoral immune responses and to potentially overcome host MHC-II polymorphisms.

  9. 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

  10. Novel IgG-Degrading Enzymes of the IgdE Protease Family Link Substrate Specificity to Host Tropism of Streptococcus Species

    PubMed Central

    Spoerry, Christian; Hessle, Pontus; Lewis, Melanie J.; Paton, Lois; Woof, Jenny M.

    2016-01-01

    Recently we have discovered an IgG degrading enzyme of the endemic pig pathogen S. suis designated IgdE that is highly specific for porcine IgG. This protease is the founding member of a novel cysteine protease family assigned C113 in the MEROPS peptidase database. Bioinformatical analyses revealed putative members of the IgdE protease family in eight other Streptococcus species. The genes of the putative IgdE family proteases of S. agalactiae, S. porcinus, S. pseudoporcinus and S. equi subsp. zooepidemicus were cloned for production of recombinant protein into expression vectors. Recombinant proteins of all four IgdE family proteases were proteolytically active against IgG of the respective Streptococcus species hosts, but not against IgG from other tested species or other classes of immunoglobulins, thereby linking the substrate specificity to the known host tropism. The novel IgdE family proteases of S. agalactiae, S. pseudoporcinus and S. equi showed IgG subtype specificity, i.e. IgdE from S. agalactiae and S. pseudoporcinus cleaved human IgG1, while IgdE from S. equi was subtype specific for equine IgG7. Porcine IgG subtype specificities of the IgdE family proteases of S. porcinus and S. pseudoporcinus remain to be determined. Cleavage of porcine IgG by IgdE of S. pseudoporcinus is suggested to be an evolutionary remaining activity reflecting ancestry of the human pathogen to the porcine pathogen S. porcinus. The IgG subtype specificity of bacterial proteases indicates the special importance of these IgG subtypes in counteracting infection or colonization and opportunistic streptococci neutralize such antibodies through expression of IgdE family proteases as putative immune evasion factors. We suggest that IgdE family proteases might be valid vaccine targets against streptococci of both human and veterinary medical concerns and could also be of therapeutic as well as biotechnological use. PMID:27749921

  11. 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

  12. Isolation and characterization of a Streptococcus pyogenes protein that binds to basal laminae of human cardiac muscle.

    PubMed Central

    Winters, B D; Ramasubbu, N; Stinson, M W

    1993-01-01

    A 9-kDa glycosaminoglycan-binding protein (GAG-BP) was isolated from Streptococcus pyogenes and purified to homogeneity by affinity chromatography on heparin-agarose. The protein selectively bound to the basal laminae of human cardiac muscle and had an apparent dissociation constant of 2.5 x 10(-7) M. Chemical analyses indicated that the GAG-BP was rich in alanine, lysine, and arginine (pI 9.5) and devoid of tyrosine, methionine, histidine, and half-cystine. There were no detectable carbohydrate or phosphate substituents. The amino acid sequence of the N terminus of GAG-BP showed homology with those of histone-like DNA-binding proteins of several other bacteria. Circular dichroism spectroscopy indicated that the protein was made up of 50% beta-sheet and 50% beta-turn and random coil in aqueous solution; however, when the protein complexed with heparin, it adopted a more ordered structure containing 25% alpha-helix, 50% beta-sheet, and 25% beta-turn and random coil. The GAG-BP cross-reacted serologically with a component of similar size in extracts of other group A streptococci and was present in the culture medium during late logarithmic growth. Images PMID:8335359

  13. 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

  14. Identification of 88 regulatory small RNAs in the TIGR4 strain of the human pathogen Streptococcus pneumoniae

    PubMed Central

    Acebo, Paloma; Martin-Galiano, Antonio J.; Navarro, Sara; Zaballos, Ángel; Amblar, Mónica

    2012-01-01

    Streptococcus pneumoniae is the main etiological agent of community-acquired pneumonia and a major cause of mortality and morbidity among children and the elderly. Genome sequencing of several pneumococcal strains revealed valuable information about the potential proteins and genetic diversity of this prevalent human pathogen. However, little is known about its transcriptional regulation and its small regulatory noncoding RNAs. In this study, we performed deep sequencing of the S. pneumoniae TIGR4 strain RNome to identify small regulatory RNA candidates expressed in this pathogen. We discovered 1047 potential small RNAs including intragenic, 5′- and/or 3′-overlapping RNAs and 88 small RNAs encoded in intergenic regions. With this approach, we recovered many of the previously identified intergenic small RNAs and identified 68 novel candidates, most of which are conserved in both sequence and genomic context in other S. pneumoniae strains. We confirmed the independent expression of 17 intergenic small RNAs and predicted putative mRNA targets for six of them using bioinformatics tools. Preliminary results suggest that one of these six is a key player in the regulation of competence development. This study is the biggest catalog of small noncoding RNAs reported to date in S. pneumoniae and provides a highly complete view of the small RNA network in this pathogen. PMID:22274957

  15. Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

    PubMed Central

    Nocek, B.; Chang, C.; Li, H.; Lezondra, L.; Holzle, D.; Collart, F.; Joachimiak, A.

    2009-01-01

    L-Proline is an amino acid that plays an important role in proteins uniquely contributing to protein folding, structure, and stability, and this amino acid serves as a sequence-recognition motif. Proline biosynthesis can occur via two pathways, one from glutamate and the other from arginine. In both pathways, the last step of biosynthesis, the conversion of Δ1-pyrroline-5-carboxylate (P5C) to L-proline, is catalyzed by Δ1-pyrroline-5-carboxylate reductase (P5CR) using NAD(P)H as a cofactor. We have determined the first crystal structure of P5CR from two human pathogens, Neisseria meningitides and Streptococcus pyogenes, at 2.0Å and 2.15Å resolution, respectively. The catalytic unit of P5CR is a dimer composed of two domains, but the biological unit seems to be species-specific. The N-terminal domain of P5CR is an α/β/α sandwich, a Rossmann fold. The C-terminal dimerization domain is rich in α-helices and shows domain swapping. Comparison of the native structure of P5CR to structures complexed with L-proline and NADP+ in two quite different primary sequence backgrounds provides unique information about key functional features: the active site and the catalytic mechanism. The inhibitory L-proline has been observed in the crystal structure. PMID:16233902

  16. Estimation of Group B Streptococcus Type III Polysaccharide-Specific Antibody Concentrations in Human Sera Is Antigen Dependent

    PubMed Central

    Bhushan, Reva; Anthony, Bascom F.; Frasch, Carl E.

    1998-01-01

    The presence of immunoglobulin G (IgG) antibodies against group B streptococcus (GBS) type III polysaccharide (PS) has been correlated with protection against GBS disease. The GBS type III PS is structurally similar to the pneumococcal type 14 PS, differing only in the presence of sialic acid residues. Four different preparations of GBS type III PS were evaluated for their specificity in enzyme-linked immunosorbent assay (ELISA): free PS, free PS mixed with methylated human serum albumin (mHSA), PS conjugated to biotin and PS conjugated to human serum albumin. Three groups of human sera were used to evaluate these PS preparations: sera from recipients of a GBS PS vaccine, sera from women receiving a GBS type III PS-tetanus toxoid conjugate vaccine, and sera from nonimmunized healthy women of childbearing age. Estimated antibody concentrations were different depending on the PS preparation used. Using any of the four preparations, we were able to measure ≤0.05 μg of IgG antibody to the GBS type III PS per ml. The specificity of the assay was determined by competitive inhibition with homologous and heterologous PS. The pneumococcal type 14 PS did not inhibit binding of antibody to the native GBS type III PS in sera from adults receiving the GBS PS vaccine or in sera from nonimmunized adults (except serum G9). The pneumococcal type 14 PS inhibited 50% in sera from recipients of GBS type III conjugate vaccine and in serum G9 when GBS type III PS conjugated to biotin or to HSA was used as antigen in ELISA. These data show that free GBS type III PS or PS mixed with mHSA is a sensitive and specific antigen for ELISA and that conjugation can alter the antigenic specificity of a PS. PMID:9826364

  17. Slaughterhouse pigs are a major reservoir of Streptococcus suis serotype 2 capable of causing human infection in southern Vietnam.

    PubMed

    Ngo, Thi Hoa; Tran, Thi Bich Chieu; Tran, Thi Thu Nga; Nguyen, Van Dung; Campbell, James; Pham, Hong Anh; Huynh, Huu Tho; Nguyen, Van Vinh Chau; Bryant, Juliet E; Tran, Tinh Hien; Farrar, Jeremy; Schultsz, Constance

    2011-03-28

    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.

  18. Identification of an Unusual Pattern of Global Gene Expression in Group B Streptococcus Grown in Human Blood

    PubMed Central

    Mereghetti, Laurent; Sitkiewicz, Izabela; Green, Nicole M.; Musser, James M.

    2009-01-01

    Because passage of the bacterium to blood is a crucial step in the pathogenesis of many group B Streptococcus (GBS) invasive infections, we recently conducted a whole-genome transcriptome analysis during GBS incubation ex vivo with human blood. In the current work, we sought to analyze in detail the difference in GBS gene expression that occurred in one blood sample (donor A) relative to other blood samples. We incubated GBS strain NEM316 with fresh heparinized human blood obtained from healthy volunteers, and analyzed GBS genome expression and cytokine production. Principal component analysis identified extensive clustering of the transcriptome data among all samples at time 0. In striking contrast, the whole bacterial gene expression in the donor A blood sample was significantly different from the gene expression in all other blood samples studied, both after 30 and 90 min of incubation. More genes were up-regulated in donor A blood relative to the other samples, at 30 min and 90 min. Furthermore, there was significant variation in transcript levels between donor A blood and other blood samples. Notably, genes with the highest transcript levels in donor A blood were those involved in carbohydrate metabolism. We also discovered an unusual production of proinflammatory and immunomodulatory cytokines: MIF, tPAI-1 and IL-1β were produced at higher levels in donor A blood relative to the other blood samples, whereas GM-CSF, TNF-α, IFN-γ, IL-7 and IL-10 remained at lower levels in donor A blood. Potential reasons for our observations are that the immune response of donor A significantly influenced the bacterial transcriptome, or both GBS gene expression and immune response were influenced by the metabolic status of donor A. PMID:19774088

  19. Effects of extracellular plaque components on the chlorhexidine sensitivity of strains of Streptococcus mutans and human dental plaque

    SciTech Connect

    Wolinsky, L.E.; Hume, W.R.

    1985-08-01

    An in vitro study was undertaken to determine the effects of sucrose-derived extracellular plaque components on the sensitivity of selected oral bacteria to chlorhexidine (CX). Cultures of Streptococcus mutans HS-6, OMZ-176, Ingbritt C, 6715-wt13, and pooled human plaque were grown in trypticase soy media with or without 1% sucrose. The sensitivity to CX of bacteria grown in each medium was determined by fixed-time exposure to CX and subsequent measurement of /sup 3/H-thymidine uptake. One-hour exposure to CX at concentrations of 10(-4) M (0.01% w/v) or greater substantially inhibited subsequent cellular division among all the S. mutans strains and human plaque samples tested. An IC50 (the CX concentration which depressed /sup 3/H-thymidine incorporation to 50% of control level) of close to 10(-4) M was noted for S. mutans strains HS-6, OMZ-176, and 6715-wt13 when grown in the presence of sucrose. The same strains grown in cultures without added sucrose showed about a ten-fold greater sensitivity to CX (IC50 close to 10(-5) M). A three-fold difference was noted for S. mutans Ingbritt C. Only a slight increase in the IC50 was noted for the plaque samples cultured in sucrose-containing media, but their threshold for depression of /sup 3/H-thymidine uptake by CX was lower than that for the sucrose-free plaque samples. The study showed that extracellular products confer some protection against CX to the bacteria examined, and provided an explanation for the disparity between clinically-recommended concentrations for plaque suppression and data on in vitro susceptibility.

  20. Bacterial Superantigens Promote Acute Nasopharyngeal Infection by Streptococcus pyogenes in a Human MHC Class II-Dependent Manner

    PubMed Central

    Kasper, Katherine J.; Zeppa, Joseph J.; Wakabayashi, Adrienne T.; Xu, Stacey X.; Mazzuca, Delfina M.; Welch, Ian; Baroja, Miren L.; Kotb, Malak; Cairns, Ewa; Cleary, P. Patrick; Haeryfar, S. M. Mansour; McCormick, John K.

    2014-01-01

    Establishing the genetic determinants of niche adaptation by microbial pathogens to specific hosts is important for the management and control of infectious disease. Streptococcus pyogenes is a globally prominent human-specific bacterial pathogen that secretes superantigens (SAgs) as ‘trademark’ virulence factors. SAgs function to force the activation of T lymphocytes through direct binding to lateral surfaces of T cell receptors and class II major histocompatibility complex (MHC-II) molecules. S. pyogenes invariably encodes multiple SAgs, often within putative mobile genetic elements, and although SAgs are documented virulence factors for diseases such as scarlet fever and the streptococcal toxic shock syndrome (STSS), how these exotoxins contribute to the fitness and evolution of S. pyogenes is unknown. Here we show that acute infection in the nasopharynx is dependent upon both bacterial SAgs and host MHC-II molecules. S. pyogenes was rapidly cleared from the nasal cavity of wild-type C57BL/6 (B6) mice, whereas infection was enhanced up to ∼10,000-fold in B6 mice that express human MHC-II. This phenotype required the SpeA superantigen, and vaccination with an MHC –II binding mutant toxoid of SpeA dramatically inhibited infection. Our findings indicate that streptococcal SAgs are critical for the establishment of nasopharyngeal infection, thus providing an explanation as to why S. pyogenes produces these potent toxins. This work also highlights that SAg redundancy exists to avoid host anti-SAg humoral immune responses and to potentially overcome host MHC-II polymorphisms. PMID:24875883

  1. Adhesion of human gingival fibroblasts/Streptococcus mitis co-culture on the nanocomposite system Chitlac-nAg.

    PubMed

    Cataldi, Amelia; Gallorini, Marialucia; Di Giulio, Mara; Guarnieri, Simone; Mariggiò, Maria Addolorata; Traini, Tonino; Di Pietro, Roberta; Cellini, Luigina; Marsich, Eleonora; Sancilio, Silvia

    2016-05-01

    Composite materials are increasingly used as dental restoration. In the field of biomaterials, infections remain the main reason of dental devices failure. Silver, in the form of nanoparticles (AgNPs), ions and salt, well known for its antimicrobial properties, is used in several medical applications in order to avoid bacterial infection. To reduce both bacterial adhesion to dental devices and cytotoxicity against eukaryotic cells, we coated BisGMA/TEGDMA methacrylic thermosets with a new material, Chitlac-nAg, formed by stabilized AgNPs with a polyelectrolyte solution containing Chitlac. Here we analyzed the proliferative and adhesive ability of human gingival fibroblasts (HGFs) on BisGMA/TEGDMA thermosets uncoated and coated with AgNPs in a coculture model system with Streptococcus mitis. After 48 h, HGFs well adhered onto both surfaces, while S. mitis cytotoxic response was higher in the presence of AgNPs coated thermosets. After 24 h thermosets coated with Chitlac as well as those coated with Chitlac-nAg exerted a minimal cytotoxic effect on HGFs, while after 48 h LDH release raised up to 20 %. Moreover the presence of S. mitis reduced this release mainly when HGFs adhered to Chitlac-nAg coated thermosets. The reduced secretion of collagen type I was significant in the presence of both surfaces with the co-culture system even more when saliva is added. Integrin β1 localized closely to cell membranes onto Chitlac-nAg thermosets and PKCα translocated into nuclei. These data confirm that Chitlac-nAg have a promising utilization in the field of restorative dentistry exerting their antimicrobial activity due to AgNPs without cytotoxicity for eukaryotic cells.

  2. The Cholesterol-Dependent Cytolysin Pneumolysin from Streptococcus pneumoniae Binds to Lipid Raft Microdomains in Human Corneal Epithelial Cells

    PubMed Central

    Taylor, Sidney D.; Sanders, Melissa E.; Tullos, Nathan A.; Stray, Stephen J.; Norcross, Erin W.; McDaniel, Larry S.; Marquart, Mary E.

    2013-01-01

    Streptococcus pneumoniae (pneumococcus) is an opportunistic bacterial pathogen responsible for causing several human diseases including pneumonia, meningitis, and otitis media. Pneumococcus is also a major cause of human ocular infections and is commonly isolated in cases of bacterial keratitis, an infection of the cornea. The ocular pathology that occurs during pneumococcal keratitis is partly due to the actions of pneumolysin (Ply), a cholesterol-dependent cytolysin produced by pneumococcus. The lytic mechanism of Ply is a three step process beginning with surface binding to cholesterol. Multiple Ply monomers then oligomerize to form a prepore. The prepore then undergoes a conformational change that creates a large pore in the host cell membrane, resulting in cell lysis. We engineered a collection of single amino acid substitution mutants at residues (A370, A406, W433, and L460) that are crucial to the progression of the lytic mechanism and determined the effects that these mutations had on lytic function. Both PlyWT and the mutant Ply molecules (PlyA370G, PlyA370E, PlyA406G, PlyA406E, PlyW433G, PlyW433E, PlyW433F, PlyL460G, and PlyL460E) were able to bind to the surface of human corneal epithelial cells (HCECs) with similar efficiency. Additionally, PlyWT localized to cholesterol-rich microdomains on the HCEC surface, however, only one mutant (PlyA370G) was able to duplicate this behavior. Four of the 9 mutant Ply molecules (PlyA370E, PlyW433G, PlyW433E, and PlyL460E) were deficient in oligomer formation. Lastly, all of the mutant Ply molecules, except PlyA370G, exhibited significantly impaired lytic activity on HCECs. The other 8 mutants all experienced a reduction in lytic activity, but 4 of the 8 retained the ability to oligomerize. A thorough understanding of the molecular interactions that occur between Ply and the target cell, could lead to targeted treatments aimed to reduce the pathology observed during pneumococcal keratitis. PMID:23577214

  3. Evaluation of hyaluronan from different sources: Streptococcus zooepidemicus, rooster comb, bovine vitreous, and human umbilical cord.

    PubMed

    Shiedlin, Aviva; Bigelow, Russell; Christopher, William; Arbabi, Saman; Yang, Laura; Maier, Ronald V; Wainwright, Norman; Childs, Alice; Miller, Robert J

    2004-01-01

    Sodium hyaluronate (HA) is widely distributed in extracellular matrixes and can play a role in orchestrating cell function. Consequently, many investigators have looked at the effect of exogenous HA on cell behavior in vitro. HA can be isolated from several sources (e.g., bacterial, rooster comb, umbilical cord) and therefore can possess diverse impurities. This current study compares the measured impurities and the differences in biological activity between HA preparations from these sources. It was demonstrated that nucleic acid and protein content was highest in human umbilical cord and bovine vitreous HA and was low in bacterial and rooster comb HA. Macrophages exposed to human umbilical cord HA produced significantly higher amounts of TNF-alpha relative to control or bacterial-derived HA. These results indicate that the source of HA should be considered due to differences in the amounts and types of contaminants that could lead to widely different behaviors in vitro and in vivo. PMID:15530025

  4. 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

  5. Real-time PCR for detection of Streptococcus suis serotype 2 in cerebrospinal fluid of human patients with meningitis

    PubMed Central

    Nga, Tran Vu Thieu; Nghia, Ho Dang Trung; Tu, Le Thi Phuong; Diep, To Song; Mai, Nguyen Thi Hoang; Chau, Tran Thi Hong; Sinh, Dinh Xuan; Phu, Nguyen Hoan; Nga, Tran Thi Thu; Chau, Nguyen Van Vinh; Campbell, James; Hoa, Ngo Thi; Chinh, Nguyen Tran; Hien, Tran Tinh; Farrar, Jeremy; Schultsz, Constance

    2011-01-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen and is the main cause of acute bacterial meningitis in adult patients in Vietnam. We developed an internally controlled real-time PCR for detection of S. suis serotype 2 in cerebrospinal fluid (CSF) samples targeted at the cps2J gene. Sensitivity and specificity in culture-confirmed clinical samples were 100%. The PCR detected S. suis serotype 2 infection in 101 of 238 (42.4%) prospectively collected CSF samples, of which 55 (23%) were culture positive. Culture-negative but PCR-positive CSF samples were significantly associated with the use of antimicrobial agents before admission. S. suis serotype 2 infection was more common than infections with Streptococcus pneumoniae and Neisseria meningitidis combined. Our results strikingly illustrate the additional diagnostic value of PCR in patients who are pretreated with antimicrobial agents and demonstrate the extremely high prevalence of S. suis infections among Vietnamese adult patients with bacterial meningitis. PMID:21767702

  6. Inhibition of the NF-kappaB pathway in human intestinal epithelial cells by commensal Streptococcus salivarius.

    PubMed

    Kaci, Ghalia; Lakhdari, Omar; Doré, Joël; Ehrlich, S Dusko; Renault, Pierre; Blottière, Hervé M; Delorme, Christine

    2011-07-01

    Streptococcus salivarius exhibited an anti-inflammatory effect on intestinal epithelial cells (IECs) and monocytes. Strains were screened using a reporter clone, HT-29/kB-luc-E, induced by tumor necrosis factor alpha (TNF-α). Supernatant from each strain downregulated NF-κB activation. The two most efficient strains produced an active metabolite (<3 kDa) which was able to downregulate the secretion of the proinflammatory chemokine interleukin-8 (IL-8). PMID:21602373

  7. Inhibition of the NF-κB Pathway in Human Intestinal Epithelial Cells by Commensal Streptococcus salivarius ▿ †

    PubMed Central

    Kaci, Ghalia; Lakhdari, Omar; Doré, Joël; Ehrlich, S. Dusko; Renault, Pierre; Blottière, Hervé M.; Delorme, Christine

    2011-01-01

    Streptococcus salivarius exhibited an anti-inflammatory effect on intestinal epithelial cells (IECs) and monocytes. Strains were screened using a reporter clone, HT-29/kB-luc-E, induced by tumor necrosis factor alpha (TNF-α). Supernatant from each strain downregulated NF-κB activation. The two most efficient strains produced an active metabolite (<3 kDa) which was able to downregulate the secretion of the proinflammatory chemokine interleukin-8 (IL-8). PMID:21602373

  8. 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

  9. Streptococcus mitis/human gingival fibroblasts co-culture: the best natural association in answer to the 2-hydroxyethyl methacrylate release.

    PubMed

    Di Giulio, Mara; D'Ercole, Simonetta; Zara, Susi; Cataldi, Amelia; Cellini, Luigina

    2012-02-01

    One of the major components of dental polymerized resin-based restorative materials is 2-hydroxyethyl methacrylate (HEMA) and its release in monomeric form interferes with the oral cavity environment. This study aimed to evaluate HEMA monomeric effects on the co-culture of Streptococcus mitis and human gingival fibroblasts (HGFs). Streptococcus mitis DS12 and S. mitis ATCC 6249 were co-cultivated with HGF in the presence of HEMA (3 mM), for 48 and 72 h; the amount of sessile and planktonic cells, as well as the prokaryotic and eukaryotic cell viability were analyzed in treated and untreated samples. The treatment of S. mitis/HGFs with HEMA did not produce significant effects on the bacterial adhesion and induced an increase in planktonic S. mitis ATCC 6249 population after 48 and 72 h. HEMA increased significantly the planktonic S. mitis ATCC 6249 viability when co-cultured with HGFs, while a cytotoxic effect on HGFs, without bacteria, was recorded. An increase of bacterial aggregation on HGFs was also detected with HEMA. Data obtained in this study suggest that HEMA exhibits a toxic effect mainly on eukaryotic cells and this effect can be modulated by co-cultivation with the S. mitis cells which, in the presence of the monomer, enhance their aggregation rate on HGFs. PMID:22229269

  10. Molecular epidemiology of mastitis pathogens of dairy cattle and comparative relevance to humans.

    PubMed

    Zadoks, Ruth N; Middleton, John R; McDougall, Scott; Katholm, Jorgen; Schukken, Ynte H

    2011-12-01

    Mastitis, inflammation of the mammary gland, can be caused by a wide range of organisms, including gram-negative and gram-positive bacteria, mycoplasmas and algae. Many microbial species that are common causes of bovine mastitis, such as Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae and Staphylococcus aureus also occur as commensals or pathogens of humans whereas other causative species, such as Streptococcus uberis, Streptococcus dysgalactiae subsp. dysgalactiae or Staphylococcus chromogenes, are almost exclusively found in animals. A wide range of molecular typing methods have been used in the past two decades to investigate the epidemiology of bovine mastitis at the subspecies level. These include comparative typing methods that are based on electrophoretic banding patterns, library typing methods that are based on the sequence of selected genes, virulence gene arrays and whole genome sequencing projects. The strain distribution of mastitis pathogens has been investigated within individual animals and across animals, herds, countries and host species, with consideration of the mammary gland, other animal or human body sites, and environmental sources. Molecular epidemiological studies have contributed considerably to our understanding of sources, transmission routes, and prognosis for many bovine mastitis pathogens and to our understanding of mechanisms of host-adaptation and disease causation. In this review, we summarize knowledge gleaned from two decades of molecular epidemiological studies of mastitis pathogens in dairy cattle and discuss aspects of comparative relevance to human medicine.

  11. Molecular epidemiology of mastitis pathogens of dairy cattle and comparative relevance to humans.

    PubMed

    Zadoks, Ruth N; Middleton, John R; McDougall, Scott; Katholm, Jorgen; Schukken, Ynte H

    2011-12-01

    Mastitis, inflammation of the mammary gland, can be caused by a wide range of organisms, including gram-negative and gram-positive bacteria, mycoplasmas and algae. Many microbial species that are common causes of bovine mastitis, such as Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae and Staphylococcus aureus also occur as commensals or pathogens of humans whereas other causative species, such as Streptococcus uberis, Streptococcus dysgalactiae subsp. dysgalactiae or Staphylococcus chromogenes, are almost exclusively found in animals. A wide range of molecular typing methods have been used in the past two decades to investigate the epidemiology of bovine mastitis at the subspecies level. These include comparative typing methods that are based on electrophoretic banding patterns, library typing methods that are based on the sequence of selected genes, virulence gene arrays and whole genome sequencing projects. The strain distribution of mastitis pathogens has been investigated within individual animals and across animals, herds, countries and host species, with consideration of the mammary gland, other animal or human body sites, and environmental sources. Molecular epidemiological studies have contributed considerably to our understanding of sources, transmission routes, and prognosis for many bovine mastitis pathogens and to our understanding of mechanisms of host-adaptation and disease causation. In this review, we summarize knowledge gleaned from two decades of molecular epidemiological studies of mastitis pathogens in dairy cattle and discuss aspects of comparative relevance to human medicine. PMID:21968538

  12. Flavonoid Glycosides Inhibit Sortase A and Sortase A-Mediated Aggregation of Streptococcus mutans, an Oral Bacterium Responsible for Human Dental Caries.

    PubMed

    Yang, Woo-Young; Kim, Chang-Kwon; Ahn, Chan-Hong; Kim, Heegyu; Shin, Jongheon; Oh, Ki-Bong

    2016-09-28

    Three flavonoids were isolated from dried flowers of Sophora japonica using repetitive column chromatography and high-performance liquid chromatography. The flavonoids were identified as rutin (1), quercetin-3'-O-methyl-3-O-α-L-rhamnopyranosyl(1 → 6)-β-D-glucopyranoside (2), and quercetin (3) on the basis of spectroscopic analysis and comparison of values reported in the literature. These compounds inhibited the action of sortase A (SrtA) from Streptococcus mutans, a primary etiologic agent of human dental caries. The onset and magnitude of inhibition of saliva-induced aggregation of S. mutans treated with compound 1 was comparable to that of untreated S. mutans with a deletion of the srtA gene. PMID:27291675

  13. Flavonoid Glycosides Inhibit Sortase A and Sortase A-Mediated Aggregation of Streptococcus mutans, an Oral Bacterium Responsible for Human Dental Caries.

    PubMed

    Yang, Woo-Young; Kim, Chang-Kwon; Ahn, Chan-Hong; Kim, Heegyu; Shin, Jongheon; Oh, Ki-Bong

    2016-09-28

    Three flavonoids were isolated from dried flowers of Sophora japonica using repetitive column chromatography and high-performance liquid chromatography. The flavonoids were identified as rutin (1), quercetin-3'-O-methyl-3-O-α-L-rhamnopyranosyl(1 → 6)-β-D-glucopyranoside (2), and quercetin (3) on the basis of spectroscopic analysis and comparison of values reported in the literature. These compounds inhibited the action of sortase A (SrtA) from Streptococcus mutans, a primary etiologic agent of human dental caries. The onset and magnitude of inhibition of saliva-induced aggregation of S. mutans treated with compound 1 was comparable to that of untreated S. mutans with a deletion of the srtA gene.

  14. 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.

  15. Structure of a conjugative element in Streptococcus pneumoniae

    SciTech Connect

    Vijayakumar, M.N.; Priebe, S.D.; Guild, W.R.

    1986-06-01

    The authors have cloned and mapped a 69-kilobase (kb) region of the chromosome of Streptococcus pneumoniae DP1322, which carries the conjugative Omega(cat-tet) insertion from S. pneumoniae BM6001. This element proved to be 65.5 kb in size. Location of the junctions was facilitated by cloning a preferred target region from the wild-type strain Rx1 recipient genome. This target site was preferred by both the BM6001 element and the cat-erm-tet element from Streptococcus agalactiae B109. Within the BM6001 element cat and tet were separated by 30 kb, and cat was flanked by two copies of a sequence that was also present in the recipient strain Rx1 DNA. Another sequence at least 2.4 kb in size was found inside the BM6001 element and at two places in the Rx1 genome. Its role is unknown. The ends of the BM6001 element appear to be the same as those of the B109 element, both as seen after transfer to S. pneumoniae and as mapped by others in pDP5 after transposition in Streptococcus faecalis. No homology is seen between the ends of the BM6001 element and no evidence found suggesting that it ever circularizes.

  16. Colostral proteins from cows immunised with Streptococcus mutans/S. sobrinus support the phagocytosis and killing of mutans streptococci by human leucocytes.

    PubMed

    Loimaranta, V; Nuutila, J; Marnila, P; Tenovuo, J; Korhonen, H; Lilius, E M

    1999-10-01

    Passive immunisation, based on bovine colostral preparations, is an area of active research. Specific bovine antibodies inhibit the virulence factors of target pathogens but the interactions between whey preparations and human immune defence cells are not well known. Bovine colostrum inhibits the phagocytic activity of bovine leucocytes and this may reflect the biological activity of immunoglobulins in it. Therefore, this study aimed to examine the effects of bovine whey protein preparations from the colostrum of Streptococcus mutans/S. sobrinus-immunised and sham-immunised cows on binding, ingestion and killing of these bacteria by human leucocytes. Binding and ingestion of FITC-labelled bacteria were estimated by flow cytometry and leukocyte activation was measured as chemiluminescence. Killing rate was estimated by plate counting and by measuring bioluminescence from S. mutans- containing the insect luciferase gene. Colostral whey protein preparation from hyperimmunised cows activated human leucocytes by opsonising specific bacteria. Neutrophils, eosinophils and monocytes weakly phagocytosed non-opsonised bacteria and bacteria opsonised with control product. On the contrary, binding and ingestion were efficient in the presence of the preparation from immunised cows. Thus, these results show that bovine colostral whey proteins are able to support the activation of human phagocytes against pathogenic microbes and that this property is related to specific antibodies in whey preparations. These whey proteins may also be clinically useful, especially in preventing the colonisation of newly erupted teeth by mutans streptococci.

  17. 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

  18. 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

  19. The role of the plasmalogen in the cross-reaction between group A streptococcus and human myocardium.

    PubMed Central

    Kasp-Grochowska, E.; Glynn, L. E.

    1977-01-01

    Ethanol-soluble mycardial material which reacts with anti-streptococcal sera in a number of immunological tests has been isolated and identified as ethanolamine plasmalogen. The reactions of cardiac plasmalogen with antistreptococcal sera was specific and could be inhibited by streptococcus-derived materials. Guinea-pigs sensitized to streptococci gave positive skin reactions when challenged with myocardial plasmalogen. The pattern of the immunofluorescent staining given by antiplasmalogen sera was very much like that given by antistreptococcal sera. Nevertheless, the plasmalogen failed to compete for tissue-bound myocardial antigens when tried as an inhibitor of the immunofluorescent staining of myocardium either by antistreptococcal sera or by antiplasmalogen sera. A hypothesis of the role of the plasmalogen in the formation of complexes between streptococci and myocardium-derived material in the initiation of autoimmune processes is presented. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:334233

  20. 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

  1. Evaluation of safety and human tolerance of the oral probiotic Streptococcus salivarius K12: a randomized, placebo-controlled, double-blind study.

    PubMed

    Burton, J P; Cowley, S; Simon, R R; McKinney, J; Wescombe, P A; Tagg, J R

    2011-09-01

    Streptococcus salivarius is naturally a predominant member of the human oropharynx and the commercial probiotic strain K12 has been consumed for more than a decade. The present study examines the health responses of human volunteers to oral ingestion of high doses of S. salivarius K12. A randomized group of 53 subjects received a dose of 1 × 10(10)cfu S. salivarius K12 (N=25) or placebo (N=28) for 28 days, followed by a 28-day wash out period. Blood, urine and saliva samples were collected at baseline and following treatment and analyzed, while the oral and gastrointestinal tolerance of the subjects to the dosing regimen was determined by use of questionnaires. Adverse events (AE)s were recorded for both groups. No statistically significant differences between the probiotic and placebo treated groups were detected in either the blood clinical chemistry or hematology results (P>0.05). The questionnaire responses of the subjects indicated that both treatments were well tolerated. The frequency and intensity of AEs was similar in the two groups. This data demonstrates that the daily ingestion of S. salivarius K12 over a 28-day period does not adversely affect the human host and supports the safety of its oral delivery in a food-based carrier. PMID:21722694

  2. Evaluation of Granada agar plate for detection of Streptococcus agalactiae in urine specimens from pregnant women.

    PubMed

    Tamayo, Javier; Gómez-Garcés, José-Luis; Alós, Juan-Ignacio

    2004-08-01

    The Granada agar plate (GAP; Biomedics SL, Madrid, Spain) was evaluated for the detection of group B streptococci (GBS) in urine specimens from pregnant women submitted for testing for asymptomatic bacteriuria and was compared with blood agar (BA [Columbia agar with 5% sheep blood]; bioMérieux, Marcy l'Etoile, France). The GAP detected 103 out of 105 GBS, whereas BA detected only 50. Use of the GAP could be a good method for the detection of GBS in urine specimens from pregnant women. PMID:15297542

  3. Pattern of infection and antibiotic activity among Streptococcus agalactiae isolates from adults in Mashhad, Iran

    PubMed Central

    Malek-Jafarian, Masoumeh; Hosseini, Fatemeh-Sadat; Ahmadi, Abodol-Reza

    2015-01-01

    Background: One of the main causes of sexually transmitted diseases is group B β- hemolytic streptococci (GBS) multiplying in the genital tracts. Penicillin is the most common drug for the treatment of infections caused by these bacteria, but in patients suffering from Penicillin allergy, Erythromycin and Clindamycin are used as alternative therapeutic drugs against GBS. Recently, resistance to these drugs has been reported more often. In this study, efforts have been made to determine the prevalence and antibiotic resistance of GBS. Methods: Modified Christie Atkins Munch-Petersen (CAMP) test was conducted on over 2400 samples of urine and discharge taken from vagina, urethra and prostate. The drug sensitivity was performed by double disk sensitivity tests to Bacitracin, Trimethoprim, and Sulfamethoxazole and then the resistant samples were investigated by E-test to determine the minimal inhibitory concentrations (MICs) value. Results: Twenty-three vaginal and 10 urethral discharge, 27urine and 6 prostatic secretion samples were GBS positive. The most symbiotic microorganisms with GBS were strains of Enterococci (90%), Staphylococcus saprophyticus (25%) and Candida albicans (6%). The disk diffusion method showed 18 cases with Penicillin resistance (MIC: 1.5 mg/ml). Conclusion: Taken together, GBS carriers’ rate in this study was found 20.65% (8.24% men and 12.4% women). Furthermore, findings showed high-level resistance to Erythromycin and Clindamycin. PMID:26989743

  4. Characterization of P40, a Cytadhesin of Mycoplasma agalactiae

    PubMed Central

    Fleury, Bénédicte; Bergonier, Dominique; Berthelot, Xavier; Peterhans, Ernst; Frey, Joachim; Vilei, Edy M.

    2002-01-01

    An immunodominant protein, P40, of Mycoplasma agalactiae was analyzed genetically and functionally. The gene encoding P40 was cloned from type strain PG2, sequenced, submitted to point mutagenesis in order to convert mycoplasma-specific TGATrp codon to the universal TGGTrp codon, and subsequently expressed in Escherichia coli. Nucleotide sequence-derived amino acid sequence comparisons revealed a similarity of P40 to the adhesin P50 of Mycoplasma hominis and to protein P89 of Spiroplasma citri, which is expected to be involved in adhesion. The amino acid sequence of P40 revealed a recognition site for a signal peptidase and strong antigenic and hydrophilic motifs in the C-terminal domain. Triton X-114 phase partitioning confirmed that P40 is a membrane protein. Fab fragments of antibodies directed against recombinant purified P40 significantly inhibited adherence of M. agalactiae strains PG2 to lamb joint synovial cells LSM 192. Sera taken sequentially from sheep infected with PG2 revealed that P40 induced a strong and persistent immune response that gave strong signals on immunoblots containing recombinant P40 even 3 months after infection. The gene encoding P40 was present in a single copy in all of the 26 field strains of M. agalactiae analyzed and was not detected in closely related mycoplasma species. P40 was expressed as a protein with an apparent molecular mass of 37 kDa on sodium dodecyl sulfate-acrylamide gels by all M. agalactiae strains except for serotype C strains, which showed nonsense mutations in their p40 genes. PMID:12228289

  5. [THE INFECTION INDUCED BY STREPTOCOCCUS OF SEROGROUP B IN PREGNANT WOMEN, PUERPERA AND NEWBORNS].

    PubMed

    Naumkina, E V; Abrosimova, O A; Pakhalkova, E V; Rogatikh, N A; Mironov A Yu

    2016-02-01

    The streptococci of serogroup B (Streptococcus agalactiae) are one of major etiologic agents responsible for occurrence of severe perinatal infections in puerpera and newborns. The prevalence of streptococci of group B is analyzed in various categories of women (stage of preconception training, pregnancy, puerpera) and newborns transferred for particular reasons to second stage of raising. The data of microbiological monitoring during four years was involved. It is established that prevalence of carriage of streptococci of serogroup B in genital tracts of women of reproductive age on territory of Omsk consists 6-8% in different categories of female patients and has no tendency to decrease. In most cases, high or moderate level of dissemination, association with other opportunistic microorganisms. The perinatal infection of premature newborns with low body mass at birth with S. agalactiae results in clinical manifestation of generalized infectious process. The infection of healthy premature newborns most often does not result in severe infectious pathology. However; in the half of all cases development of local (significantly more rarely - generalized) pyoinflammatory induced by S. agalactiae as both isolated and in association with other opportunistic microorganisms. The relatively high rate of realization of potential of agent in newborns of risk group requires attention to the issues of diagnostic of carriage of streptococci group B in pregnant women, inclusion of this type of analysis into standards of observation for given category of female patients with purpose of timely sanitation, development and elaboration of standards of laboratory analysis on this agent. PMID:27455565

  6. Role of Vpma phase variation in Mycoplasma agalactiae pathogenesis

    PubMed Central

    Chopra-Dewasthaly, Rohini; Baumgartner, Martina; Gamper, Erika; Innerebner, Carmen; Zimmermann, Martina; Schilcher, Franz; Tichy, Alexander; Winter, Petra; Rosengarten, Renate; Spergser, Joachim

    2015-01-01

    Compared with other bacterial pathogens, the molecular mechanisms of mycoplasma pathogenicity are largely unknown. Several studies in the past have shown that pathogenic mycoplasmas are equipped with sophisticated genetic systems that allow them to undergo high-frequency surface antigenic variations. Although never clearly proven, these variable mycoplasma surface components are often implicated in host immune evasion and adaptation. Vpma surface lipoproteins of the ruminant pathogen Mycoplasma agalactiae are encoded on a genomic pathogenicity island–like locus and are considered as one of the well-characterized model systems of mycoplasma surface antigenic variation. The present study assesses the role of these phase-variable Vpmas in the molecular pathogenesis of M. agalactiae by testing the wild-type strain PG2 in comparison with the xer1-disrupted Vpma ‘phase-locked’ mutants in sheep infection models. The data clearly illustrate that although Xer1 recombinase is not a virulence factor of M. agalactiae and Vpma phase variation is not necessary for establishing an infection, it might critically influence the survival and persistence of the pathogen under natural field conditions, mainly due to a better capacity for dissemination and evoking systemic responses. This is the first study where mycoplasma ‘phase-locked’ mutants are tested in vivo to elucidate the role of phase variation during infection. PMID:22809092

  7. Distribution of Streptococcus troglodytae and Streptococcus dentirousetti in chimpanzee oral cavities.

    PubMed

    Miyanohara, Mayu; Imai, Susumu; Okamoto, Masaaki; Saito, Wataru; Nomura, Yoshiaki; Momoi, Yasuko; Tomonaga, Masaki; Hanada, Nobuhiro

    2013-05-01

    The aim of this study was to analyze the distribution and phenotypic properties of the indigenous streptococci in chimpanzee (Pan troglodytes) oral cavities. Eleven chimpanzees (aged from 9 to 44 years, mean ± SD, 26.9 ± 12.6 years) in the Primate Research Institute of Kyoto University were enrolled in this research and brushing bacterial samples collected from them. Streptococci were isolated from the oral cavities of all chimpanzees. The isolates (n = 46) were identified as thirteen species by 16S rRNA genes analysis. The predominant species was Streptococcus sanguinis of mitis streptococci from five chimpanzees (45%). Mutans streptococci were isolated from six chimpanzees (55%). The predominant species in the mutans streptococci were Streptococcus troglodytae from four chimpanzees (36%), this species having been proposed as a novel species by us, and Streptococcus dentirousetti from three chimpanzees (27%). Streptococcus mutans was isolated from one chimpanzee (9%). However, Streptococcus sobrinus, Streptococcus macacae and Streptococcus downei, which are indigenous to human and monkey (Macaca fasciclaris) oral habitats, were not isolated. Of the mutans streptococci, S. troglodytae, S. dentirousetti, and S. mutans possessed strong adherence activity to glass surface.

  8. Quorum-Sensing Systems LuxS/Autoinducer 2 and Com Regulate Streptococcus pneumoniae Biofilms in a Bioreactor with Living Cultures of Human Respiratory Cells

    PubMed Central

    Howery, Kristen E.; Ludewick, Herbert P.; Nava, Porfirio; Klugman, Keith P.

    2013-01-01

    Streptococcus pneumoniae forms organized biofilms in the human upper respiratory tract that may play an essential role in both persistence and acute respiratory infection. However, the production and regulation of biofilms on human cells is not yet fully understood. In this work, we developed a bioreactor with living cultures of human respiratory epithelial cells (HREC) and a continuous flow of nutrients, mimicking the microenvironment of the human respiratory epithelium, to study the production and regulation of S. pneumoniae biofilms (SPB). SPB were also produced under static conditions on immobilized HREC. Our experiments demonstrated that the biomass of SPB increased significantly when grown on HREC compared to the amount on abiotic surfaces. Additionally, pneumococcal strains produced more early biofilms on lung cells than on pharyngeal cells. Utilizing the bioreactor or immobilized human cells, the production of early SPB was found to be regulated by two quorum-sensing systems, Com and LuxS/AI-2, since a mutation in either comC or luxS rendered the pneumococcus unable to produce early biofilms on HREC. Interestingly, while LuxS/autoinducer 2 (AI-2) regulated biofilms on both HREC and abiotic surfaces, Com control was specific for those structures produced on HREC. The biofilm phenotypes of strain D39-derivative ΔcomC and ΔluxS QS mutants were reversed by genetic complementation. Of note, SPB formed on immobilized HREC and incubated under static conditions were completely lysed 24 h postinoculation. Biofilm lysis was also regulated by the Com and LuxS/AI-2 quorum-sensing systems. PMID:23403556

  9. Molecular cloning and biochemical characterization of Xaa-Pro dipeptidyl-peptidase from Streptococcus mutans and its inhibition by anti-human DPP IV drugs.

    PubMed

    De, Arpan; Lupidi, Giulio; Petrelli, Dezemona; Vitali, Luca A

    2016-05-01

    Streptococcus mutans harbours an intracellular, human DPP IV-analogous enzyme Xaa-Pro dipeptidyl-peptidase (EC 3.4.14.11). According to previous reports, an extracellular isozyme in S. gordonii and S. suis has been associated with virulence. Speculating that even an intracellular form may aid in virulence of S. mutans, we have tried to purify, characterize and evaluate enzyme inhibition by specific inhibitors. The native enzyme was partially purified by ion-exchange and gel filtration chromatography. Owing to low yield, the enzyme was overexpressed in Lactococcus lactis and purified by affinity chromatography. The recombinant enzyme (rSm-XPDAP) had a specific activity of 1070 U mg(-1), while the Vmax and Km were 7 μM min(-1) and 89 ± 7 μM (n = 3), respectively. The serine protease inhibitor phenylmethylsulphonyl fluoride and a DPP IV-specific inhibitor diprotin A proved to be active against rSm-XPDAP. As a novel approach, the evaluation of the effect of anti-human DPP IV (AHD) drugs on rSm-XPDAP activity found saxagliptin to be effective to some extent (Ki = 129 ± 16 μM), which may lead to the synthesis and development of a new class of antimicrobial agents. PMID:27010012

  10. Heterologous expression and purification of biologically active domains 3 and 4 of human polymeric immunoglobulin receptor and its interaction with choline binding protein A of Streptococcus pneumoniae.

    PubMed

    Venables, Luanne; Govender, Sharlene; Oosthuizen, Vaughan

    2013-10-01

    Streptococcus pneumoniae, one of the common causes of pneumonia, colonises the epithelium via the interaction between a choline binding protein of S. pneumoniae and the human polymeric immunoglobulin receptor (pIgR). One of the functions of pIgR is to mediate the transcytosis of polymeric immunoglobulins from the basolateral to the apical surface of epithelial cells. S. pneumoniae invades human epithelial cells by exploiting the transcytosis machinery. Due to an increase in the prevalence of antibiotic resistant strains of S. pneumoniae, and the limitations and expense of the vaccines available, extensive research may provide insights into the potential of new therapeutic regimes. This study investigated the potential of pIgR domains as an alternative non-antibiotic immune therapy for treating pneumonia. The aim was to determine the binding affinity of recombinant D3D4 protein, the domains of pIgR responsible for binding S. pneumoniae, to recombinant R1R2 repeat domains of choline binding protein A of S. pneumoniae. Biologically active recombinant D3D4 was produced in Escherichia coli using a gel filtration chromatography refolding method, a novel approach for the refolding of pIgR domains, after the purification of inclusion bodies using nickel affinity chromatography. Surface Plasmon resonance (SPR) spectroscopy showed that purified recombinant D3D4 binds recombinant R1R2 with an equilibrium dissociation constant (KD) of 3.36×10(-7)M. PMID:23973337

  11. Tricuspid valve endocarditis with Group B Streptococcus after an elective abortion: the need for new data.

    PubMed

    Palys, Erica E; Li, John; Gaut, Paula L; Hardy, W David

    2006-01-01

    Streptococcus agalactiae, commonly known as Group B streptococcus (GBS), was originally discovered as a cause of bovine mastitis. GBS colonizes the genital tract of up to 40% of women and has become a major pathogen in neonatal meningitis. GBS endocarditis is thought to be an uncommon manifestation of this infection and carries a higher mortality compared to other streptococcal pathogens. Studies have shown that endocarditis after abortion has an incidence of about one per million. However, this figure was published prior to routine use of echocardiography for diagnosis. The American Heart Association has recently declared transesophageal echocardiography the gold standard for endocarditis diagnosis. This case report illustrates that, given the potentially devastating consequences of endocarditis, there is a need for updated studies to adequately assess the true incidence of this infection. Pending the outcome of these studies, routine GBS screening and prophylactic antibiotics prior to abortion should be recommended.

  12. Seroepidemiological survey of sheep flocks from Northern Japan for Mycoplasma ovipneumoniae and Mycoplasma agalactiae.

    PubMed

    Giangaspero, Massimo; Nicholas, Robin A J; Hlusek, Miroslav; Bonfini, Barbara; Osawa, Takeshi; Orusa, Riccardo; Tatami, Shingo; Takagi, Eishu; Moriya, Hiroaki; Okura, Norimoto; Kato, Kazuo; Kimura, Atsushi; Harasawa, Ryô; Ayling, Roger D

    2012-03-01

    Sheep flocks from Hokkaido, Iwate and Aomori, three northern prefectures of Japan, were screened for antibodies to Mycoplasma ovipneumoniae and Mycoplasma agalactiae by ELISA. Sixty four animals out of 246 (26%) were seropositive to M. ovipneumoniae, with positive results obtained from all three prefectures. None of the sera tested were serologically positive to M. agalactiae.

  13. Extensive diversity of Streptococcus pyogenes in a remote human population reflects global-scale transmission rather than localised diversification.

    PubMed

    Towers, Rebecca J; Carapetis, Jonathan R; Currie, Bart J; Davies, Mark R; Walker, Mark J; Dougan, Gordon; Giffard, Philip M

    2013-01-01

    The Indigenous population of the Northern Territory of Australia (NT) suffers from a very high burden of Streptococcus pyogenes disease, including cardiac and renal sequelae. The aim of this study was to determine if S. pyogenes isolated from this population represent NT endemic strains, or conversely reflect strains with global distribution. emm sequence typing data were used to select 460 S. pyogenes isolates representing NT S. pyogenes diversity from 1987-2008. These isolates were genotyped using either multilocus sequence typing (MLST) or a high resolution melting-based MLST surrogate (Minim typing). These data were combined with MLST data from other studies on NT S. pyogenes to yield a set of 731 MLST or Minim typed isolates for analysis. goeBURST analysis of MLST allelic profiles and neighbour-joining trees of the MLST allele sequences revealed that a large proportion of the known global S. pyogenes MLST-defined diversity has now been found in the NT. Specifically, fully sequence typed NT isolates encompass 19% of known S. pyogenes STs and 43% of known S. pyogenes MLST alleles. These analyses provided no evidence for major NT-endemic strains, with many STs and MLST alleles shared between the NT and the rest of the world. The relationship between the number of known Minim types, and the probability that a Minim type identified in a calendar year would be novel was determined. This revealed that Minim types typically persist in the NT for >1 year, and indicate that the majority of NT Minim types have been identified. This study revealed that many diverse S. pyogenes strains exhibit global scale mobility that extends to isolated populations. The burden of S. pyogenes disease in the NT is unlikely to be due to the nature of NT S. pyogenes strains, but is rather a function of social and living conditions.

  14. 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

  15. Short communication: Streptococcus species isolated from mastitis milk samples in Germany and their resistance to antimicrobial agents.

    PubMed

    Minst, K; Märtlbauer, E; Miller, T; Meyer, C

    2012-12-01

    Mastitis is one of the most frequent infectious diseases in dairy cattle and is a reason for antimicrobial drug usage in dairy cows. The bacteria involved in bovine mastitis are mainly Streptococcus spp., Staphylococcus spp., and coliforms. The aim of this study was to determine antimicrobial resistance among Streptococcus spp. isolated from bovine mastitis milk. Antimicrobial resistance in Strep. uberis (n=227), Strep. dysgalactiae (n=49), and Strep. agalactiae (n=3) was determined for 9 antimicrobial agents using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute recommendations. Of all Streptococcus spp., 13% were multidrug resistant. The rate of multidrug resistance was higher among Strep. uberis (15%) than among Strep. dysgalactiae (6%) and Strep. agalactiae (0%). Resistance to tetracycline was the most common, followed by resistance to erythromycin, pirlimycin, and gentamicin. Resistance rates were higher on farms with more than 80 cows compared with those with fewer than 20 cows. β-Lactams should remain the drugs of choice in the treatment of streptococcal mastitis. The slightly elevated minimum inhibitory concentrations determined for these antibiotics may indicate, however, the emergence of resistant streptococci. To identify such changes in susceptibility as early as possible, antimicrobial resistance in streptococci should be surveyed regularly. PMID:22999286

  16. Mycoplasma agalactiae Induces Cytopathic Effects in Infected Cells Cultured In Vitro

    PubMed Central

    Hegde, Shrilakshmi; Hegde, Shivanand Manjunath; Rosengarten, Renate; Chopra-Dewasthaly, Rohini

    2016-01-01

    Mycoplasma agalactiae is the etiological agent of the contagious agalactia syndrome in sheep and goats and causes significant economic losses worldwide. Yet the mechanism of pathogenesis is largely unknown. Even whole-genome sequence analysis of its pathogenic type strain did not lead to any conclusions regarding its virulence or pathogenicity factors. Although inflammation and tissue destruction at the local site of M. agalactiae infection are largely considered as effects of the host immune response, the direct effect of the agent on host cells is not completely understood. The aim of this study was to investigate the effect of M. agalactiae infection on the quality and viability of host cells in vitro. Changes in cell morphology including cell elongation, cytoplasm shrinkage and membrane blebbing were observed in infected HeLa cells. Chromatin condensation and increased caspase-3 cleavage in infected HeLa cells 48 h after infection suggests an apoptosis-like phenomenon in M. agalactiae-infected cells. In compliance with these results, decreased viability and cell lysis of M. agalactiae-infected HeLa cells was also observed. Measurement of the amount of LDH released after M. agalactiae infection revealed a time- and dose-dependent increase in HeLa cell lysis. A significant decrease in LDH released after gentamicin treatment of infected cells confirmed the major role of cytadherent M. agalactiae in inducing host cell lysis. This is the first study illustrating M. agalactiae’s induction of cytopathic effects in infected HeLa cells. Further detailed investigation of infected host tissue for apoptotic markers might demonstrate the association between M. agalactiae-induced host cell lysis and the tissue destruction observed during M. agalactiae natural infection. PMID:27662492

  17. Lactobacillus plantarum reduces Streptococcus pyogenes virulence by modulating the IL-17, IL-23 and Toll-like receptor 2/4 expressions in human epithelial cells.

    PubMed

    Rizzo, Antonietta; Losacco, Antonio; Carratelli, Caterina Romano; Domenico, Marina Di; Bevilacqua, Nazario

    2013-10-01

    Streptococcus pyogenes is a common colonizer of the mucosal layers in the mouth, nose, and pharynx but it is also a major Gram-positive human pathogen that causes infections ranging from pharyngitis to severe systemic diseases. The lactobacilli colonize the oral tracts and are known to protect against colonization by many pathogens. Epithelial cells participate in the innate host defense by expressing a variety of proinflammatory cytokines and TLRs in the interaction with microorganisms. The potentially probiotic strain Lactobacillus plantarum was investigated for its capacity to influence the innate immune response of HEp-2 and A549 epithelial cells to S. pyogenes infection. In both epithelial cell types, pre-treatment with L. plantarum showed inhibition of S. pyogenes growth and a greater decrease in IL-17 and IL-23 levels compared to the control. Pre-treatment with the anti-TLR2/4 antibody abolished the inhibitory effects of L. plantarum on IL-17 and IL-23 production following S. pyogenes infection, indicating that L. plantarum downregulates TLR2/4-dependent IL-17 and IL-23 production. Overall, our findings suggest that in epithelial cell cultures with S. pyogenes, cytokine responses are modulated by the presence of L. plantarum through the induction of TLR2/TLR4.

  18. Clonal Diversity and Turnover of Streptococcus mitis bv. 1 on Shedding and Nonshedding Oral Surfaces of Human Infants during the First Year of Life

    PubMed Central

    Kirchherr, Jennifer L.; Bowden, George H.; Richmond, Dorothy A.; Sheridan, Michael J.; Wirth, Katherine A.; Cole, Michael F.

    2005-01-01

    Streptococcus mitis bv. 1 is a pioneer colonizer of the human oral cavity. Studies of its population dynamics within parents and their infants and within neonates have shown extensive diversity within and between subjects. We examined the genetic diversity and clonal turnover of S. mitis bv. 1 isolated from the cheeks, tongue, and primary incisors of four infants from birth to 1 year of age. In addition, we compared the clonotypes of S. mitis bv. 1 isolated from their mothers' saliva collected in parallel to determine whether the mother was the origin of the clones colonizing her infant. Of 859 isolates obtained from the infants, 568 were unique clones. Each of the surfaces examined, whether shedding or nonshedding, displayed the same degree of diversity. Among the four infants it was rare to detect the same clone colonizing more than one surface at a given visit. There was little evidence for persistence of clones, but when clones were isolated on multiple visits they were not always found on the same surface. A similar degree of clonal diversity of S. mitis bv. 1 was observed in the mothers' saliva as in their infants' mouths. Clones common to both infant and mothers' saliva were found infrequently suggesting that this is not the origin of the infants' clones. It is unclear whether mucosal immunity exerts the environmental pressure driving the genetic diversity and clonal turnover of S. mitis bv. 1, which may be mechanisms employed by this bacterium to evade immune elimination. PMID:16210481

  19. Feasibility and Safety of Local Treatment with Recombinant Human Tissue Factor Pathway Inhibitor in a Rat Model of Streptococcus pneumoniae Pneumonia

    PubMed Central

    van den Boogaard, Florry E.; Hofstra, Jorrit J.; van ‘t Veer, Cornelis; Levi, Marcel M.; Roelofs, Joris J. T. H.; van der Poll, Tom; Schultz, Marcus J.

    2015-01-01

    Pulmonary coagulopathy is intrinsic to pulmonary injury including pneumonia. Anticoagulant strategies could benefit patients with pneumonia, but systemic administration of anticoagulant agents may lead to suboptimal local levels and may cause systemic hemorrhage. We hypothesized nebulization to provide a safer and more effective route for local administration of anticoagulants. Therefore, we aimed to examine feasibility and safety of nebulization of recombinant human tissue factor pathway inhibitor (rh-TFPI) in a well-established rat model of Streptococcus (S.) pneumoniae pneumonia. Thirty minutes before and every 6 hours after intratracheal instillation of S. pneumonia causing pneumonia, rats were subjected to local treatment with rh-TFPI or placebo, and sacrificed after 42 hours. Pneumonia was associated with local as well as systemic activation of coagulation. Nebulization of rh-TFPI resulted in high levels of rh-TFPI in bronchoalveolar lavage fluid, which was accompanied by an attenuation of pulmonary coagulation. Systemic rh-TFPI levels remained undetectable, and systemic TFPI activity and systemic coagulation were not affected. Histopathology revealed no bleeding in the lungs. We conclude that nebulization of rh-TFPI seems feasible and safe; local anticoagulant treatment with rh-TFPI attenuates pulmonary coagulation, while not affecting systemic coagulation in a rat model of S. pneumoniae pneumonia. PMID:25992779

  20. Candida albicans and Streptococcus salivarius modulate IL-6, IL-8, and TNF-alpha expression and secretion by engineered human oral mucosa cells.

    PubMed

    Mostefaoui, Yakout; Bart, Christian; Frenette, Michel; Rouabhia, Mahmoud

    2004-11-01

    We investigated the involvement of oral epithelial cells via two cytokines (IL-6 and TNF-alpha) and one chemokine (IL-8) in local defences against live yeast (Candida albicans) and bacteria (Streptococcus salivarius) using an engineered human oral mucosa model. We report that the yeast changed from the blastospore to the hyphal form and induced significant tissue disorganization at later contact periods (24 and 48 h) compared to the bacteria. However, this effect did not reduce the viability or total number of epithelial cells. Gene activation analyses revealed that IL-6, IL-8 and TNF-alpha mRNA levels rose in tissues in contact with live C. albicans or S. salivarius. Gene activation was followed by an upregulation of protein secretion. IL-6 levels were higher after contact with C. albicans than with S. salivarius. IL-8 levels after contact with S. salivarius were higher than with C. albicans. Our study suggests that S. salivarius is more efficient at inducing proinflammatory mediator release than C. albicans. These results provide additional evidence for the contribution of oral epithelial cells to the inflammatory response against fungi and bacteria. PMID:15469436

  1. A simple, quantitative, reproducible avidin-biotin ELISA for the evaluation of group B streptococcus type-specific antibodies in humans.

    PubMed

    Basham, L E; Pavliak, V; Li, X; Hawwari, A; Kotloff, K L; Edelman, R; Fattom, A

    1996-04-01

    Type-specific antibodies to the capsular polysaccharides (CP) of group B Streptococcus (GBS) are protective. Historically, the radioactive antigen-binding assay (RABA) has been used to determine GBS antibody levels. This method measures total immunoglobulin and employs the use of radioactive materials. We have developed an avidin-biotin ELISA that is less hazardous and is able to measure GBS Ia, Ib, II or III CP specific IgG. To avoid inconsistent binding to the plate, the CPs from GBS Ia, Ib, II and III were derivatized using adipic acid dihydrazide (ADH) and subsequently biotinylated without altering their antigenic epitopes and bound to avidin coated plates. Plasma from three different human subjects immunized with a tetravalent CP vaccine were used to prepare IgG references for Ia, II and III, respectively, thus rendering the assay quantitative for those types. The assay is able to detect nanograms per milliliter of GBS Ia, Ib, II or III specific antibody. This method is reproducible, sensitive and correlates with RABA by 76%. PMID:8735557

  2. The commensal Streptococcus salivarius K12 downregulates the innate immune responses of human epithelial cells and promotes host-microbe homeostasis.

    PubMed

    Cosseau, Celine; Devine, Deirdre A; Dullaghan, Edie; Gardy, Jennifer L; Chikatamarla, Avinash; Gellatly, Shaan; Yu, Lorraine L; Pistolic, Jelena; Falsafi, Reza; Tagg, John; Hancock, Robert E W

    2008-09-01

    Streptococcus salivarius is an early colonizer of human oral and nasopharyngeal epithelia, and strain K12 has reported probiotic effects. An emerging paradigm indicates that commensal bacteria downregulate immune responses through the action on NF-kappaB signaling pathways, but additional mechanisms underlying probiotic actions are not well understood. Our objective here was to identify host genes specifically targeted by K12 by comparing their responses with responses elicited by pathogens and to determine if S. salivarius modulates epithelial cell immune responses. RNA was extracted from human bronchial epithelial cells (16HBE14O- cells) cocultured with K12 or bacterial pathogens. cDNA was hybridized to a human 21K oligonucleotide-based array. Data were analyzed using ArrayPipe, InnateDB, PANTHER, and oPOSSUM. Interleukin 8 (IL-8) and growth-regulated oncogene alpha (Groalpha) secretion were determined by enzyme-linked immunosorbent assay. It was demonstrated that S. salivarius K12 specifically altered the expression of 565 host genes, particularly those involved in multiple innate defense pathways, general epithelial cell function and homeostasis, cytoskeletal remodeling, cell development and migration, and signaling pathways. It inhibited baseline IL-8 secretion and IL-8 responses to LL-37, Pseudomonas aeruginosa, and flagellin in epithelial cells and attenuated Groalpha secretion in response to flagellin. Immunosuppression was coincident with the inhibition of activation of the NF-kappaB pathway. Thus, the commensal and probiotic behaviors of S. salivarius K12 are proposed to be due to the organism (i) eliciting no proinflammatory response, (ii) stimulating an anti-inflammatory response, and (iii) modulating genes associated with adhesion to the epithelial layer and homeostasis. S. salivarius K12 might thereby ensure that it is tolerated by the host and maintained on the epithelial surface while actively protecting the host from inflammation and apoptosis

  3. The Commensal Streptococcus salivarius K12 Downregulates the Innate Immune Responses of Human Epithelial Cells and Promotes Host-Microbe Homeostasis▿ †

    PubMed Central

    Cosseau, Celine; Devine, Deirdre A.; Dullaghan, Edie; Gardy, Jennifer L.; Chikatamarla, Avinash; Gellatly, Shaan; Yu, Lorraine L.; Pistolic, Jelena; Falsafi, Reza; Tagg, John; Hancock, Robert E. W.

    2008-01-01

    Streptococcus salivarius is an early colonizer of human oral and nasopharyngeal epithelia, and strain K12 has reported probiotic effects. An emerging paradigm indicates that commensal bacteria downregulate immune responses through the action on NF-κB signaling pathways, but additional mechanisms underlying probiotic actions are not well understood. Our objective here was to identify host genes specifically targeted by K12 by comparing their responses with responses elicited by pathogens and to determine if S. salivarius modulates epithelial cell immune responses. RNA was extracted from human bronchial epithelial cells (16HBE14O- cells) cocultured with K12 or bacterial pathogens. cDNA was hybridized to a human 21K oligonucleotide-based array. Data were analyzed using ArrayPipe, InnateDB, PANTHER, and oPOSSUM. Interleukin 8 (IL-8) and growth-regulated oncogene alpha (Groα) secretion were determined by enzyme-linked immunosorbent assay. It was demonstrated that S. salivarius K12 specifically altered the expression of 565 host genes, particularly those involved in multiple innate defense pathways, general epithelial cell function and homeostasis, cytoskeletal remodeling, cell development and migration, and signaling pathways. It inhibited baseline IL-8 secretion and IL-8 responses to LL-37, Pseudomonas aeruginosa, and flagellin in epithelial cells and attenuated Groα secretion in response to flagellin. Immunosuppression was coincident with the inhibition of activation of the NF-κB pathway. Thus, the commensal and probiotic behaviors of S. salivarius K12 are proposed to be due to the organism (i) eliciting no proinflammatory response, (ii) stimulating an anti-inflammatory response, and (iii) modulating genes associated with adhesion to the epithelial layer and homeostasis. S. salivarius K12 might thereby ensure that it is tolerated by the host and maintained on the epithelial surface while actively protecting the host from inflammation and apoptosis induced by

  4. Group B Streptococcal Infection and Activation of Human Astrocytes

    PubMed Central

    Stoner, Terri D.; Weston, Thomas A.; Trejo, JoAnn; Doran, Kelly S.

    2015-01-01

    Background Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of life-threatening meningitis in human newborns in industrialized countries. Meningitis results from neonatal infection that occurs when GBS leaves the bloodstream (bacteremia), crosses the blood-brain barrier (BBB), and enters the central nervous system (CNS), where the bacteria contact the meninges. Although GBS is known to invade the BBB, subsequent interaction with astrocytes that physically associate with brain endothelium has not been well studied. Methodology/Principal Findings We hypothesize that human astrocytes play a unique role in GBS infection and contribute to the development of meningitis. To address this, we used a well- characterized human fetal astrocyte cell line, SVG-A, and examined GBS infection in vitro. We observed that all GBS strains of representative clinically dominant serotypes (Ia, Ib, III, and V) were able to adhere to and invade astrocytes. Cellular invasion was dependent on host actin cytoskeleton rearrangements, and was specific to GBS as Streptococcus gordonii failed to enter astrocytes. Analysis of isogenic mutant GBS strains deficient in various cell surface organelles showed that anchored LTA, serine-rich repeat protein (Srr1) and fibronectin binding (SfbA) proteins all contribute to host cell internalization. Wild-type GBS also displayed an ability to persist and survive within an intracellular compartment for at least 12 h following invasion. Moreover, GBS infection resulted in increased astrocyte transcription of interleukin (IL)-1β, IL-6 and VEGF. Conclusions/Significance This study has further characterized the interaction of GBS with human astrocytes, and has identified the importance of specific virulence factors in these interactions. Understanding the role of astrocytes during GBS infection will provide important information regarding BBB disruption and the development of neonatal meningitis. PMID:26030618

  5. Salivary mucin 19 glycoproteins: innate immune functions in Streptococcus mutans-induced caries in mice and evidence for expression in human saliva.

    PubMed

    Culp, David J; Robinson, Bently; Cash, Melanie N; Bhattacharyya, Indraneel; Stewart, Carol; Cuadra-Saenz, Giancarlo

    2015-01-30

    Saliva functions in innate immunity of the oral cavity, protecting against demineralization of teeth (i.e. dental caries), a highly prevalent infectious disease associated with Streptococcus mutans, a pathogen also linked to endocarditis and atheromatous plaques. Gel-forming mucins are a major constituent of saliva. Because Muc19 is the dominant salivary gel-forming mucin in mice, we studied Muc19(-/-) mice for changes in innate immune functions of saliva in interactions with S. mutans. When challenged with S. mutans and a cariogenic diet, total smooth and sulcal surface lesions are more than 2- and 1.6-fold higher in Muc19(-/-) mice compared with wild type, whereas the severity of lesions are up to 6- and 10-fold higher, respectively. Furthermore, the oral microbiota of Muc19(-/-) mice display higher levels of indigenous streptococci. Results emphasize the importance of a single salivary constituent in the innate immune functions of saliva. In vitro studies of S. mutans and Muc19 interactions (i.e. adherence, aggregation, and biofilm formation) demonstrate Muc19 poorly aggregates S. mutans. Nonetheless, aggregation is enhanced upon adding Muc19 to saliva from Muc19(-/-) mice, indicating Muc19 assists in bacterial clearance through formation of heterotypic complexes with salivary constituents that bind S. mutans, thus representing a novel innate immune function for salivary gel-forming mucins. In humans, expression of salivary MUC19 is unclear. We find MUC19 transcripts in salivary glands of seven subjects and demonstrate MUC19 glycoproteins in glandular mucous cells and saliva. Similarities and differences between mice and humans in the expression and functions of salivary gel-forming mucins are discussed. PMID:25512380

  6. 21 CFR 526.1696d - Penicillin G procaine-novobiocin for intramammary infusion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... by susceptible strains of Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae... caused by susceptible strains of Staphylococcus aureus and Streptococcus agalactiae. (iii)...

  7. 21 CFR 526.1696d - Penicillin G procaine-novobiocin for intramammary infusion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... by susceptible strains of Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae... caused by susceptible strains of Staphylococcus aureus and Streptococcus agalactiae. (iii)...

  8. 21 CFR 526.1696d - Penicillin G procaine-novobiocin for intramammary infusion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... susceptible strains of Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and... caused by susceptible strains of Staphylococcus aureus and Streptococcus agalactiae. (iii)...

  9. 21 CFR 526.1696d - Penicillin G procaine-novobiocin for intramammary infusion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... by susceptible strains of Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae... caused by susceptible strains of Staphylococcus aureus and Streptococcus agalactiae. (iii)...

  10. 21 CFR 526.1696d - Penicillin G procaine-novobiocin for intramammary infusion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... by susceptible strains of Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae... caused by susceptible strains of Staphylococcus aureus and Streptococcus agalactiae. (iii)...

  11. Aggregation of Streptococcus pneumoniae by a pneumococcal capsular polysaccharide-specific human monoclonal IgM correlates with antibody efficacy in vivo.

    PubMed

    Fabrizio, Kevin; Manix, Catherine; Guimaraes, Allan J; Nosanchuk, Joshua D; Pirofski, Liise-Anne

    2010-05-01

    Acquired antibody immunity to Streptococcus pneumoniae (pneumococcus) has been linked to serotype (ST)-specific opsonic antibodies to the relevant pneumococcal capsular polysaccharide (PPS) that mediate protection by enhancing the bactericidal effect of host phagocytes. Despite the well-recognized role of opsonic IgG in host defense against pneumococcus, PPS-specific monoclonal antibodies (MAbs) that mediate protection against lethal challenge with ST3 pneumococcus in mice but do not promote phagocytic killing in vitro (nonopsonic antibodies) have been described. In this study, we sought to determine the biological activity of one such MAb, A7 (a human PPS3-specific IgM), and the mechanism by which it mediates protection. In vitro studies demonstrated that coincubation of A7 with ST3 in the absence of phagocytes or a complement source resulted in a reduction in CFU on blood agar plates that was largely reversible by sonication. A chromogenic cellular proliferation assay demonstrated that A7 did not affect replication of ST3 in liquid culture. The ability of A7 to induce aggregation of ST3 was confirmed by fluorescence microscopy and flow cytometry: A7 induced aggregation of ST3, and in the presence of a complement source, A7 promoted deposition of complement component 3 (C3) on aggregated bacteria in a dose-dependent fashion. Similarly, administration of preincubated mixtures of A7 and ST3 intraperitoneally to mice protected them from the lethality of ST3 in a dose-dependent fashion. These findings suggest that A7-mediated aggregation enhances resistance to ST3, most likely by enhancing C3 deposition on the ST3 capsule, thereby promoting host antipneumococcal activity in vivo.

  12. Small plasmids in Streptococcus dysgalactiae subsp. equisimilis isolated from human infections in southern India and sequence analysis of two novel plasmids.

    PubMed

    Bergmann, René; Nitsche-Schmitz, D Patric

    2015-05-01

    Small plasmids are frequently found in S. pyogenes isolates from human infections in India. Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a streptococcal subspecies that is genetically similar to S. pyogenes and has a similar ecology. Therefore, we determined the distribution of small plasmids in a collection of 254 SDSE isolates, comprising 44 different emm-types and emm non-typable strains, from southern India, utilizing an established PCR based method. Briefly, 1.2% (n=3) of the isolates were positive for repA (encoding the replication initiation protein A) and 1.6% (n=4) were repB positive (encoding the replication initiation protein B). One isolate (G315) showed a co-detection of repB and dysA (encoding the bacteriocin dysgalacticin) which is characteristic for previously described pDN281/pW2580-like plasmids, observed in SDSE and S. pyogenes. The remaining plasmid bearing isolates showed no characteristic co-detection of known plasmid-associated genes. Thus, plasmids pG271 and pG279, representatives for repB and repA harboring plasmids, respectively, were analyzed. The plasmids pG271 and pG279 could be assigned to the pMV158 and the pC194/pUB110 family of rolling-circle plasmids, respectively. Like the characterized small native plasmids of S. pyogenes from India, the SDSE plasmids discovered and described in this study did not carry any of the known antibiotic resistance genes. SDSE bore less of the investigated small native plasmids that were distinct from the small native plasmids of S. pyogenes of the same geographic region. This indicates a low rate of lateral transfer of these genetic elements between these two related streptococcal species.

  13. Pneumolysin-dependent and -independent gene expression identified by cDNA microarray analysis of THP-1 human mononuclear cells stimulated by Streptococcus pneumoniae.

    PubMed

    Rogers, P David; Thornton, Justin; Barker, Katherine S; McDaniel, D Olga; Sacks, Gordon S; Swiatlo, Edwin; McDaniel, Larry S

    2003-04-01

    Pneumolysin is an important virulence factor of Streptococcus pneumoniae, interacting with the membranes of host cells to elicit a multitude of inflammatory responses. We used cDNA microarrays to identify genes which are responsive to S. pneumoniae in a pneumolysin-dependent and -independent fashion. The THP-1 human monocytic cell line was coincubated for 3 h with medium alone, with the virulent type 2 S. pneumoniae strain D39, or with the isogenic strain PLN, which does not express pneumolysin. RNA was isolated from the monocytes and hybridized on cDNA microarrays. Of 4,133 genes evaluated, 142 were found to be responsive in a pneumolysin-dependent fashion, whereas 40 were found to be responsive independent of pneumolysin. Genes that were up-regulated in cells exposed to D39 relative to those exposed to PLN included genes encoding proteins such as mannose binding lectin 1, lysozyme, alpha-1 catenin, cadherin 17, caspases 4 and 6, macrophage inflammatory protein 1beta (MIP-1beta), interleukin 8 (IL-8), monocyte chemotactic protein 3 (MCP-3), IL-2 receptor beta (IL-2Rbeta), IL-15 receptor alpha (IL-15Ralpha), interferon receptor 2, and prostaglandin E synthase. Down-regulated genes included those encoding complement component receptor 2/CD21, platelet-activating factor acetylhydrolase, and oxidized low-density lipoprotein receptor 1 (OLR1). Pneumolysin-independent responses included down-regulation of the genes encoding CD68, CD53, CD24, transforming growth factor beta2, and signal transducers and activators of transcription 1. These results demonstrate the striking effects of pneumolysin on the host cell upon exposure to S. pneumoniae.

  14. Plasma-derived human C1-esterase inhibitor does not prevent mechanical ventilation-induced pulmonary complement activation in a rat model of Streptococcus pneumoniae pneumonia.

    PubMed

    de Beer, F M; Aslami, H; Hoeksma, J; van Mierlo, G; Wouters, D; Zeerleder, S; Roelofs, J J T H; Juffermans, N P; Schultz, M J; Lagrand, W K

    2014-11-01

    Mechanical ventilation has the potential to cause lung injury, and the role of complement activation herein is uncertain. We hypothesized that inhibition of the complement cascade by administration of plasma-derived human C1-esterase inhibitor (C1-INH) prevents ventilation-induced pulmonary complement activation, and as such attenuates lung inflammation and lung injury in a rat model of Streptococcus pneumoniae pneumonia. Forty hours after intratracheal challenge with S. pneumoniae causing pneumonia rats were subjected to ventilation with lower tidal volumes and positive end-expiratory pressure (PEEP) or high tidal volumes without PEEP, after an intravenous bolus of C1-INH (200 U/kg) or placebo (saline). After 4 h of ventilation blood, broncho-alveolar lavage fluid and lung tissue were collected. Non-ventilated rats with S. pneumoniae pneumonia served as controls. While ventilation with lower tidal volumes and PEEP slightly amplified pneumonia-induced complement activation in the lungs, ventilation with higher tidal volumes without PEEP augmented local complement activation more strongly. Systemic pre-treatment with C1-INH, however, failed to alter ventilation-induced complement activation with both ventilation strategies. In accordance, lung inflammation and lung injury were not affected by pre-treatment with C1-INH, neither in rats ventilated with lower tidal volumes and PEEP, nor rats ventilated with high tidal volumes without PEEP. Ventilation augments pulmonary complement activation in a rat model of S. pneumoniae pneumonia. Systemic administration of C1-INH, however, does not attenuate ventilation-induced complement activation, lung inflammation, and lung injury. PMID:24760631

  15. A novel initiation mechanism of death in Streptococcus pneumoniae induced by the human milk protein-lipid complex HAMLET and activated during physiological death.

    PubMed

    Clementi, Emily A; Marks, Laura R; Duffey, Michael E; Hakansson, Anders P

    2012-08-01

    To cause colonization or infection, most bacteria grow in biofilms where differentiation and death of subpopulations is critical for optimal survival of the whole population. However, little is known about initiation of bacterial death under physiological conditions. Membrane depolarization has been suggested, but never shown to be involved, due to the difficulty of performing such studies in bacteria and the paucity of information that exists regarding ion transport mechanisms in prokaryotes. In this study, we performed the first extensive investigation of ion transport and membrane depolarization in a bacterial system. We found that HAMLET, a human milk protein-lipid complex, kills Streptococcus pneumoniae (the pneumococcus) in a manner that shares features with activation of physiological death from starvation. Addition of HAMLET to pneumococci dissipated membrane polarity, but depolarization per se was not enough to trigger death. Rather, both HAMLET- and starvation-induced death of pneumococci specifically required a sodium-dependent calcium influx, as shown using calcium and sodium transport inhibitors. This mechanism was verified under low sodium conditions, and in the presence of ionomycin or monensin, which enhanced pneumococcal sensitivity to HAMLET- and starvation-induced death. Pneumococcal death was also inhibited by kinase inhibitors, and indicated the involvement of Ser/Thr kinases in these processes. The importance of this activation mechanism was made evident, as dysregulation and manipulation of physiological death was detrimental to biofilm formation, a hallmark of bacterial colonization. Overall, our findings provide novel information on the role of ion transport during bacterial death, with the potential to uncover future antimicrobial targets.

  16. Effect of peroral immunization of humans with Streptococcus mutans on induction of salivary and serum antibodies and inhibition of experimental infection.

    PubMed Central

    Cole, M F; Emilson, C G; Hsu, S D; Li, S H; Bowen, W H

    1984-01-01

    Naturally occurring antibodies reactive with Streptococcus mutans whole cells were assayed in whole saliva, parotid saliva, and blood samples collected from eight human volunteers. The levels and serotypes of indigenous S. mutans in plaque and whole saliva samples were also determined. After baseline sampling the teeth were cleaned and the subjects were inoculated with streptomycin-resistant S. mutans strains Ingbritt (serotype c) and OMZ65 (serotype g). The level of implantation and duration of colonization were determined in plaque and saliva, and antibodies reactive with these strains were monitored in saliva and serum. After the implanted bacteria were shed, the subjects wee immunized by the daily ingestion of an enteric-coated capsule containing 25 mg of Formalin-killed, freeze-dried OMZ65 cells for 3 days and inoculation was repeated. The levels of antibodies and of implantation and the duration of colonization were monitored as before. One month after the bacteria could no longer be detected, the immunization and inoculation cycle was repeated except that the subjects were immunized for 7 days. Five of the eight subjects were successfully colonized by strains Ingbritt and OMZ65. The remaining three did not become colonized with either strain. Strain OMZ65 implanted at a higher level than did strain Ingbritt. Oral immunization did not result in a detectable antibody response in saliva or serum to whole bacterial cells. However, after both the first and second immunizations there were marked reductions in the peak levels of infection and the duration of colonization of both OMZ65 and Ingbritt. PMID:6389359

  17. A Novel Initiation Mechanism of Death in Streptococcus pneumoniae Induced by the Human Milk Protein-Lipid Complex HAMLET and Activated during Physiological Death*

    PubMed Central

    Clementi, Emily A.; Marks, Laura R.; Duffey, Michael E.; Hakansson, Anders P.

    2012-01-01

    To cause colonization or infection, most bacteria grow in biofilms where differentiation and death of subpopulations is critical for optimal survival of the whole population. However, little is known about initiation of bacterial death under physiological conditions. Membrane depolarization has been suggested, but never shown to be involved, due to the difficulty of performing such studies in bacteria and the paucity of information that exists regarding ion transport mechanisms in prokaryotes. In this study, we performed the first extensive investigation of ion transport and membrane depolarization in a bacterial system. We found that HAMLET, a human milk protein-lipid complex, kills Streptococcus pneumoniae (the pneumococcus) in a manner that shares features with activation of physiological death from starvation. Addition of HAMLET to pneumococci dissipated membrane polarity, but depolarization per se was not enough to trigger death. Rather, both HAMLET- and starvation-induced death of pneumococci specifically required a sodium-dependent calcium influx, as shown using calcium and sodium transport inhibitors. This mechanism was verified under low sodium conditions, and in the presence of ionomycin or monensin, which enhanced pneumococcal sensitivity to HAMLET- and starvation-induced death. Pneumococcal death was also inhibited by kinase inhibitors, and indicated the involvement of Ser/Thr kinases in these processes. The importance of this activation mechanism was made evident, as dysregulation and manipulation of physiological death was detrimental to biofilm formation, a hallmark of bacterial colonization. Overall, our findings provide novel information on the role of ion transport during bacterial death, with the potential to uncover future antimicrobial targets. PMID:22700972

  18. Streptococcus-Zebrafish Model of Bacterial Pathogenesis

    PubMed Central

    Neely, Melody N.; Pfeifer, John D.; Caparon, Michael

    2002-01-01

    Due to its small size, rapid generation time, powerful genetic systems, and genomic resources, the zebrafish has emerged as an important model of vertebrate development and human disease. Its well-developed adaptive and innate cellular immune systems make the zebrafish an ideal model for the study of infectious diseases. With a natural and important pathogen of fish, Streptococcus iniae, we have established a streptococcus- zebrafish model of bacterial pathogenesis. Following injection into the dorsal muscle, zebrafish developed a lethal infection, with a 50% lethal dose of 103 CFU, and died within 2 to 3 days. The pathogenesis of infection resembled that of S. iniae in farmed fish populations and that of several important human streptococcal diseases and was characterized by an initial focal necrotic lesion that rapidly progressed to invasion of the pathogen into all major organ systems, including the brain. Zebrafish were also susceptible to infection by the human pathogen Streptococcus pyogenes. However, disease was characterized by a marked absence of inflammation, large numbers of extracellular streptococci in the dorsal muscle, and extensive myonecrosis that occurred far in advance of any systemic invasion. The genetic systems available for streptococci, including a novel method of mutagenesis which targets genes whose products are exported, were used to identify several mutants attenuated for virulence in zebrafish. This combination of a genetically amenable pathogen with a well-defined vertebrate host makes the streptococcus-zebrafish model of bacterial pathogenesis a powerful model for analysis of infectious disease. PMID:12065534

  19. The novel species Streptococcus tigurinus and its association with oral infection.

    PubMed

    Zbinden, Andrea; Bostanci, Nagihan; Belibasakis, Georgios N

    2015-01-01

    Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. S. tigurinus belongs to the Streptococcus mitis group and is most closely related to Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae and Streptococcus infantis. The presence of S. tigurinus in the human oral cavity has been documented, including in patients with periodontal disease. This review addresses the available scientific knowledge on S. tigurinus and its association with closely related streptococci, and discusses its putative involvement in common oral infections. While there is as yet no strong evidence on the involvement of S. tigurinus with oral infections, its presence in the oral cavity and its association with endocarditis warrants special attention for a link between oral and systemic infection.

  20. Streptococcus bovis meningitis and hemorrhoids.

    PubMed

    Smith, Adam Hewitt; Sra, Harminder K; Bawa, Sandeep; Stevens, Richard

    2010-07-01

    We report a case of Streptococcus bovis (Streptococcus gallolyticus subsp. pasteurianus) meningitis, a rare cause of central nervous system (CNS) infection in an adult, and comment on the importance of investigation of the lower gastrointestinal tract to identify a portal of entry in cases of systemic Streptococcus bovis infection. PMID:20421434

  1. Short communication: In vitro antimicrobial susceptibility of Mycoplasma agalactiae strains isolated from dairy goats.

    PubMed

    Paterna, A; Sánchez, A; Gómez-Martín, A; Corrales, J C; De la Fe, C; Contreras, A; Amores, J

    2013-01-01

    This study examined the susceptibility to several antimicrobials of 28 isolates of Mycoplasma agalactiae obtained from goats in a region (southeastern Spain) where contagious agalactia is endemic. For each isolate, the minimum inhibitory concentration (MIC) against 12 antimicrobials of the quinolone, macrolide, aminoglycoside, and tetracycline families was determined. The antimicrobials with the lowest MIC were enrofloxacin, ciprofloxacin, tylosin, and doxycycline, all with MIC90 (concentration at which growth of 90% of the isolates is inhibited) <1 µg/mL. Norfloxacin (a quinolone) showed a wide MIC range (0.1-12.8 µg/mL), suggesting a resistance mechanism toward this antimicrobial that was not elicited by enrofloxacin or ciprofloxacin (the other quinolones tested). Erythromycin showed the highest MIC90 such that its use against Mycoplasma agalactiae is not recommended. Finally, Mycoplasma agalactiae isolates obtained from goat herds with clinical symptoms of contagious agalactia featured higher MIC90 and MIC50 (concentration at which growth of 50% of the isolates is inhibited) values for many of the antimicrobials compared with isolates from asymptomatic animals. The relationship between the extensive use of antimicrobials in herds with clinical contagious agalactia and variations in MIC requires further study. PMID:24035026

  2. 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

  3. Simultaneous measurement of the viability, aggregation, and live and dead adherence of Streptococcus crista, Streptococcus mutans and Actinobacillus actinomycetemcomitans in human saliva in relation to indices of caries, dental plaque and periodontal disease.

    PubMed

    Rudney, J D; Staikov, R K

    2002-05-01

    Salivary proteins have multiple functions and many share similar functions, which may be why it has been difficult to relate variations in their concentrations to oral health and ecology. An alternative is to focus on variations in the major functions of saliva. An hydroxyapatite-coated microplate model has been developed that simultaneously measures saliva-promoted bacterial viability, bacterial aggregation, and live and dead bacterial adherence, while simulating oral temperature and shearing forces from swallowing. That model was applied to resting whole and stimulated parotid saliva from 149 individuals, using representative strains of Streptococcus crista, S. mutans, and Actinobacillus actinomycetemcomitans. Two major factors were defined by multivariate analysis (this was successful only for whole-saliva). One factor was correlated with aggregation, live adherence and dead adherence for all three strains; the other was correlated with total viability of all three strains. Participants were grouped <25th percentile and >75th percentile for each factor. Those groups were compared for clinical indices of oral health. Caries scores were significantly lower in those with high scores for aggregation-adherence, regardless of whether total viability scores were low or high. Live bacteria always predominated on surfaces when live and dead adherence scores were expressed as ratios. However, participants with high scores for aggregation-adherence showed significantly more dead adherent bacteria than those with low scores (these ratios were uncorrelated with total viability). This finding may indicate that extreme differences in the ability to kill bacteria on surfaces can influence caries risk.

  4. 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

  5. Serologic studies of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus morbillorum by crossed immunoelectrophoresis.

    PubMed

    Coleman, R M; Lambe, D W

    1979-07-01

    A reference antigen-antibody system for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus morbillorum was established with crossed immunoelectrophoresis. A comparison of S. intermedius, S. constellatus, and S. morbillorum with crossed immunoelectrophoresis and crossed immunoelectrophoresis with intermediate gel indicated that S. intermedius and S. constellatus are closely related antigenically with as many as six common cytoplasmic antigens. S. morbillorum was antigenically more distinct; antiserum of one strain of S. morbillorum was monospecific, indicating that specific serogroups of S. morbillorum exist. Crossed immunoelectrophoresis and tandem crossed immunoelectrophoresis revealed that S. intermedius, S. constellatus, and S. morbillorum also share some common antigens with Streptococcus sanguis and Streptococcus mitis, but S. intermedius, S. constellatus, and S. morbillorum are antigenically distinct from Streptococcus mutans and Streptococcus bovis.

  6. Genomics, evolution, and molecular epidemiology of the Streptococcus bovis/Streptococcus equinus complex (SBSEC).

    PubMed

    Jans, Christoph; Meile, Leo; Lacroix, Christophe; Stevens, Marc J A

    2015-07-01

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a group of human and animal derived streptococci that are commensals (rumen and gastrointestinal tract), opportunistic pathogens or food fermentation associates. The classification of SBSEC has undergone massive changes and currently comprises 7 (sub)species grouped into four branches based on sequences identities: the Streptococcus gallolyticus, the Streptococcus equinus, the Streptococcus infantarius and the Streptococcus alactolyticus branch. In animals, SBSEC are causative agents for ruminal acidosis, potentially laminitis and infective endocarditis (IE). In humans, a strong association was established between bacteraemia, IE and colorectal cancer. Especially the SBSEC-species S. gallolyticus subsp. gallolyticus is an emerging pathogen for IE and prosthetic joint infections. S. gallolyticus subsp. pasteurianus and the S. infantarius branch are further associated with biliary and urinary tract infections. Knowledge on pathogenic mechanisms is so far limited to colonization factors such as pili and biofilm formation. Certain strain variants of S. gallolyticus subsp. macedonicus and S. infantarius subsp. infantarius are associated with traditional dairy and plant-based food fermentations and display traits suggesting safety. However, due to their close relationship to virulent strains, their use in food fermentation has to be critically assessed. Additionally, implementing accurate and up-to-date taxonomy is critical to enable appropriate treatment of patients and risk assessment of species and strains via recently developed multilocus sequence typing schemes to enable comparative global epidemiology. Comparative genomics revealed that SBSEC strains harbour genomics islands (GI) that seem acquired from other streptococci by horizontal gene transfer. In case of virulent strains these GI frequently encode putative virulence factors, in strains from food fermentation the GI encode functions that are

  7. Genomics, evolution, and molecular epidemiology of the Streptococcus bovis/Streptococcus equinus complex (SBSEC).

    PubMed

    Jans, Christoph; Meile, Leo; Lacroix, Christophe; Stevens, Marc J A

    2015-07-01

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a group of human and animal derived streptococci that are commensals (rumen and gastrointestinal tract), opportunistic pathogens or food fermentation associates. The classification of SBSEC has undergone massive changes and currently comprises 7 (sub)species grouped into four branches based on sequences identities: the Streptococcus gallolyticus, the Streptococcus equinus, the Streptococcus infantarius and the Streptococcus alactolyticus branch. In animals, SBSEC are causative agents for ruminal acidosis, potentially laminitis and infective endocarditis (IE). In humans, a strong association was established between bacteraemia, IE and colorectal cancer. Especially the SBSEC-species S. gallolyticus subsp. gallolyticus is an emerging pathogen for IE and prosthetic joint infections. S. gallolyticus subsp. pasteurianus and the S. infantarius branch are further associated with biliary and urinary tract infections. Knowledge on pathogenic mechanisms is so far limited to colonization factors such as pili and biofilm formation. Certain strain variants of S. gallolyticus subsp. macedonicus and S. infantarius subsp. infantarius are associated with traditional dairy and plant-based food fermentations and display traits suggesting safety. However, due to their close relationship to virulent strains, their use in food fermentation has to be critically assessed. Additionally, implementing accurate and up-to-date taxonomy is critical to enable appropriate treatment of patients and risk assessment of species and strains via recently developed multilocus sequence typing schemes to enable comparative global epidemiology. Comparative genomics revealed that SBSEC strains harbour genomics islands (GI) that seem acquired from other streptococci by horizontal gene transfer. In case of virulent strains these GI frequently encode putative virulence factors, in strains from food fermentation the GI encode functions that are

  8. 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

  9. Antepartum screening for group B Streptococcus by three FDA-cleared molecular tests and effect of shortened enrichment culture on molecular detection rates.

    PubMed

    Couturier, Brianne A; Weight, Trent; Elmer, Haley; Schlaberg, Robert

    2014-09-01

    Neonatal Streptococcus agalactiae infections cause significant morbidity and mortality, and antenatal screening is recommended. We compared three U.S. Food and Drug Administration (FDA)-cleared nucleic acid amplification tests (NAATs) to culture using 314 vaginal/rectal swabs after 18 to 24 h (recommended period) and 4 to 8 h (shortened period) of broth enrichment. Agreement of the NAATs with each other was high (97.1% to 98.4%), but culture was less sensitive than all NAATs (67% to 73%). A shortened period of broth culture enrichment resulted in 1 false-negative result in 68 (1.5%). The NAATs performed comparably and were more sensitive than culture.

  10. Anti-bacterial activity of recombinant human β-defensin-3 secreted in the milk of transgenic goats produced by somatic cell nuclear transfer.

    PubMed

    Liu, Jun; Luo, Yan; Ge, Hengtao; Han, Chengquan; Zhang, Hui; Wang, Yongsheng; Su, Jianmin; Quan, Fusheng; Gao, Mingqing; Zhang, Yong

    2013-01-01

    The present study was conducted to determine whether recombinant human β-defensin-3 (rHBD3) in the milk of transgenic goats has an anti-bacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Streptococcus agalactiae (S. agalactiae) that could cause mastitis. A HBD3 mammary-specific expression vector was transfected by electroporation into goat fetal fibroblasts which were used to produce fourteen healthy transgenic goats by somatic cell nuclear transfer. The expression level of rHBD3 in the milk of the six transgenic goats ranged from 98 to 121 µg/ml at 15 days of lactation, and was maintained at 90-111 µg/ml during the following 2 months. Milk samples from transgenic goats showed an obvious inhibitory activity against E. coli, S. aureus and S. agalactiae in vitro. The minimal inhibitory concentrations of rHBD3 in milk against E. coli, S. aureus and S. agalactiae were 9.5-10.5, 21.8-23.0 and 17.3-18.5 µg/mL, respectively, which was similar to those of the HBD3 standard (P>0.05). The in vivo anti-bacterial activities of rHBD3 in milk were examined by intramammary infusion of viable bacterial inoculums. We observed that 9/10 and 8/10 glands of non-transgenic goats infused with S. aureus and E. coli became infected. The mean numbers of viable bacteria went up to 2.9×10(3) and 95.4×10(3) CFU/ml at 48 h after infusion, respectively; the mean somatic cell counts (SCC) in infected glands reached up to 260.4×10(5) and 622.2×10(5) cells/ml, which were significantly higher than the SCC in uninfected goat glands. In contrast, no bacteria was presented in glands of transgenic goats and PBS-infused controls, and the SSC did not significantly change throughout the period. Moreover, the compositions and protein profiles of milk from transgenic and non-transgenic goats were identical. The present study demonstrated that HBD3 were an effective anti-bacterial protein to enhance the mastitis resistance of dairy animals.

  11. Anti-Bacterial Activity of Recombinant Human β-Defensin-3 Secreted in the Milk of Transgenic Goats Produced by Somatic Cell Nuclear Transfer

    PubMed Central

    Han, Chengquan; Zhang, Hui; Wang, Yongsheng; Su, Jianmin; Quan, Fusheng; Gao, Mingqing; Zhang, Yong

    2013-01-01

    The present study was conducted to determine whether recombinant human β-defensin-3 (rHBD3) in the milk of transgenic goats has an anti-bacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Streptococcus agalactiae (S. agalactiae) that could cause mastitis. A HBD3 mammary-specific expression vector was transfected by electroporation into goat fetal fibroblasts which were used to produce fourteen healthy transgenic goats by somatic cell nuclear transfer. The expression level of rHBD3 in the milk of the six transgenic goats ranged from 98 to 121 µg/ml at 15 days of lactation, and was maintained at 90–111 µg/ml during the following 2 months. Milk samples from transgenic goats showed an obvious inhibitory activity against E. coli, S. aureus and S. agalactiae in vitro. The minimal inhibitory concentrations of rHBD3 in milk against E. coli, S. aureus and S. agalactiae were 9.5–10.5, 21.8–23.0 and 17.3–18.5 µg/mL, respectively, which was similar to those of the HBD3 standard (P>0.05). The in vivo anti-bacterial activities of rHBD3 in milk were examined by intramammary infusion of viable bacterial inoculums. We observed that 9/10 and 8/10 glands of non-transgenic goats infused with S. aureus and E. coli became infected. The mean numbers of viable bacteria went up to 2.9×103 and 95.4×103 CFU/ml at 48 h after infusion, respectively; the mean somatic cell counts (SCC) in infected glands reached up to 260.4×105 and 622.2×105 cells/ml, which were significantly higher than the SCC in uninfected goat glands. In contrast, no bacteria was presented in glands of transgenic goats and PBS-infused controls, and the SSC did not significantly change throughout the period. Moreover, the compositions and protein profiles of milk from transgenic and non-transgenic goats were identical. The present study demonstrated that HBD3 were an effective anti-bacterial protein to enhance the mastitis resistance of dairy animals. PMID:23799010

  12. Functional analysis of glucan binding protein B from Streptococcus mutans.

    PubMed

    Mattos-Graner, Renata O; Porter, Kristen A; Smith, Daniel J; Hosogi, Yumiko; Duncan, Margaret J

    2006-06-01

    Mutans streptococci are major etiological agents of dental caries, and several of their secreted products contribute to bacterial accumulation on teeth. Of these, Streptococcus mutans glucan binding protein B (GbpB) is a novel, immunologically dominant protein. Its biological function is unclear, although GbpB shares homology with a putative peptidoglycan hydrolase from S. agalactiae and S. pneumoniae, indicative of a role in murein biosynthesis. To determine the cellular function of GbpB, we used several approaches to inactivate the gene, analyze its expression, and identify interacting proteins. None of the transformants analyzed were true gbpB mutants, since they all contained both disrupted and wild-type gene copies, and expression of functional GbpB was always conserved. Thus, the inability to obtain viable gbpB null mutants supports the notion that gbpB is an essential gene. Northern blot and real-time PCR analyses suggested that induction of gbpB expression in response to stress was a strain-dependent phenomenon. Proteins that interacted with GbpB were identified in pull-down and coimmunoprecipitation assays, and these data suggest that GbpB interacts with ribosomal protein L7/L12, possibly as part of a protein complex involved in peptidoglycan synthesis and cell division. PMID:16707674

  13. Developing oral probiotics from Streptococcus salivarius.

    PubMed

    Wescombe, Philip A; Hale, John D F; Heng, Nicholas C K; Tagg, John R

    2012-12-01

    Considerable human illness can be linked to the development of oral microbiota disequilibria. The predominant oral cavity commensal, Streptococcus salivarius has emerged as an important source of safe and efficacious probiotics, capable of fostering more balanced, health-associated oral microbiota. Strain K12, the prototype S. salivarius probiotic, originally introduced to counter Streptococcus pyogenes infections, now has an expanded repertoire of health-promoting applications. K12 and several more recently proposed S. salivarius probiotics are now being applied to control diverse bacterial consortia infections including otitis media, halitosis and dental caries. Other potential applications include upregulation of immunological defenses against respiratory viral infections and treatment of oral candidosis. An overview of the key steps required for probiotic development is also presented. PMID:23231486

  14. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices...

  15. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices...

  16. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720 Section 866.3720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices...

  17. Novel Streptococcus infantarius subsp. infantarius variants harboring lactose metabolism genes homologous to Streptococcus thermophilus.

    PubMed

    Jans, Christoph; Gerber, Andrea; Bugnard, Joséphine; Njage, Patrick Murigu Kamau; Lacroix, Christophe; Meile, Leo

    2012-08-01

    Streptococcus infantarius subsp. infantarius belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC) commonly associated with human and animal infections. We elucidated the lactose metabolism of S. infantarius subsp. infantarius predominant in African fermented milk products. S. infantarius subsp. infantarius isolates (n = 192) were identified in 88% of spontaneously fermented camel milk suusac samples (n = 24) from Kenya and Somalia at log₁₀ 8.2-8.5 CFU mL⁻¹. African S. infantarius isolates excreted stoichiometric amounts of galactose when grown on lactose, exhibiting a metabolism similar to Streptococcus thermophilus and distinct from their type strain. African S. infantarius subsp. infantarius CJ18 harbors a regular gal operon with 99.7-100% sequence identity to S. infantarius subsp. infantarius ATCC BAA-102(T) and a gal-lac operon with 91.7-97.6% sequence identity to S. thermophilus, absent in all sequenced SBSEC strains analyzed. The expression and functionality of lacZ was demonstrated in a β-galactosidase assay. The gal-lac operon was identified in 100% of investigated S. infantarius isolates (n = 46) from suusac samples and confirmed in Malian fermented cow milk isolates. The African S. infantarius variant potentially evolved through horizontal gene transfer of an S. thermophilus-homologous lactose pathway. Safety assessments are needed to identify any putative health risks of this novel S. infantarius variant. PMID:22475940

  18. Novel Streptococcus infantarius subsp. infantarius variants harboring lactose metabolism genes homologous to Streptococcus thermophilus.

    PubMed

    Jans, Christoph; Gerber, Andrea; Bugnard, Joséphine; Njage, Patrick Murigu Kamau; Lacroix, Christophe; Meile, Leo

    2012-08-01

    Streptococcus infantarius subsp. infantarius belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC) commonly associated with human and animal infections. We elucidated the lactose metabolism of S. infantarius subsp. infantarius predominant in African fermented milk products. S. infantarius subsp. infantarius isolates (n = 192) were identified in 88% of spontaneously fermented camel milk suusac samples (n = 24) from Kenya and Somalia at log₁₀ 8.2-8.5 CFU mL⁻¹. African S. infantarius isolates excreted stoichiometric amounts of galactose when grown on lactose, exhibiting a metabolism similar to Streptococcus thermophilus and distinct from their type strain. African S. infantarius subsp. infantarius CJ18 harbors a regular gal operon with 99.7-100% sequence identity to S. infantarius subsp. infantarius ATCC BAA-102(T) and a gal-lac operon with 91.7-97.6% sequence identity to S. thermophilus, absent in all sequenced SBSEC strains analyzed. The expression and functionality of lacZ was demonstrated in a β-galactosidase assay. The gal-lac operon was identified in 100% of investigated S. infantarius isolates (n = 46) from suusac samples and confirmed in Malian fermented cow milk isolates. The African S. infantarius variant potentially evolved through horizontal gene transfer of an S. thermophilus-homologous lactose pathway. Safety assessments are needed to identify any putative health risks of this novel S. infantarius variant.

  19. Laboratory growth and maintenance of Streptococcus pyogenes (the Group A Streptococcus, GAS).

    PubMed

    Gera, Kanika; McIver, Kevin S

    2013-10-02

    Streptococcus pyogenes is a Gram-positive bacterium that strictly infects humans. It is the causative agent of a broad spectrum of diseases accounting for millions of infections and at least 517,000 deaths each year worldwide. It is a nutritionally fastidious organism that ferments sugars to produce lactic acid and has strict requirements for growth. To aid in the study of this organism, this unit describes the growth and maintenance of S. pyogenes.

  20. Laboratory Growth and Maintenance of Streptococcus pyogenes (The Group A Streptococcus, GAS)

    PubMed Central

    Gera, Kanika; McIver, Kevin S.

    2013-01-01

    Streptococcus pyogenes is a Gram-positive bacterium that strictly infects humans. It is the causative agent of a broad spectrum of diseases accounting for millions of infections and at least 517, 000 deaths each year worldwide (Carapetis et al., 2005). It is a nutritionally fastidious organism that ferments sugars to produce lactic acid and has strict requirements for growth. To aid in the study of this organism, this unit describes the growth and maintenance of S. pyogenes. PMID:24510893

  1. 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

  2. Characterization and Analysis of a Stable Serotype-Associated Membrane Protein (P30) of Mycoplasma agalactiae

    PubMed Central

    Fleury, Bénédicte; Bergonier, Dominique; Berthelot, Xavier; Schlatter, Yvonne; Frey, Joachim; Vilei, Edy M.

    2001-01-01

    The gene for a 30-kDa immunodominant antigen, P30, of Mycoplasma agalactiae was cloned from type strain PG2 and expressed in Escherichia coli. P30 is encoded on a monocistronic operon determined by two −10 boxes and a possible −35 region constituting the potential promoter, and a transcription termination site. The gene for the 266-amino-acid protein is preceded by a polypurine-rich region designed as the consensus sequence for a ribosome-binding site. Analysis of the amino acid sequence of P30 revealed the presence of a recognition site for a prokaryotic signal peptidase II at amino acid (aa) 24, indicating that P30 is a transmembrane protein. Moreover, Triton X-114 phase partitioning of M. agalactiae PG2 total antigen revealed that P30 is strongly hydrophobic and hence a possible membrane component. Immunoblot analysis using the monospecific polyclonal anti-P30-His serum indicated that P30 is specific to M. agalactiae. Furthermore, PCR amplification with specific primers for p30 and Southern blot analysis revealed the presence of the gene in all M. agalactiae strains tested and its absence in the other mycoplasma species. Among 27 strains of M. agalactiae studied, 20 strains belonging to the common serotypes A to D, including PG2, expressed P30 or part of it as detected by the monospecific polyclonal anti-P30 antibodies. The other seven strains belonging to the rarely isolated serotypes E to H were negative for P30. The p30 gene was sequenced in 15 strains of M. agalactiae, 10 of which expressed P30 or at least part of it and 5 of which did not express P30. The negative strains carried mutations in both −10 boxes of the promoters. These mutations seem to be responsible for the lack of P30 expression in these strains. Analysis of sera from sheep that were experimentally infected with M. agalactiae revealed that P30 induced a strong and persistent immune response which was still very high two months after infection. In contrast, currently used enzyme

  3. A microwave-irradiated Streptococcus agalactiae vaccine provides partial protection against experimental challenge in Nile tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microwave irradiation, as opposed to formalin exposure, has not routinely been used in the preparation of killed vaccines despite the advantages of decreased chemical toxicity, ability to kill cells quickly, ease of completion requiring only a standard microwave, and potential increased protein cons...

  4. Survey of strain distribution and antibiotic resistance pattern of group B streptococci (Streptococcus agalactiae) isolated from clinical specimens

    PubMed Central

    Mousavi, Seyed Masoud; Nasaj, Mona; Hosseini, Seyed Mostafa; Arabestani, Mohammad Reza

    2016-01-01

    Aim: The aims of the present study were to determine the antibiotic susceptibility profils with particular emphasis on susceptible or resistant strains to macrolides and lincosamids antibiotics and to determine possible antibiotic resistance mechanisms occurring in group B streptococci (GBS) strains using PCR assay and disk diffusion method. Methods: A total of 62 clinical GBS strains were investigated. Antibacterial susceptibility testing was performed using the disk diffusion method and inducible resistance test for clindamycin by standard double disk diffusion or D-zone test for all isolates to differentiate macrolide resistance phenotype (M), constitutive macrolide-lincosamide-streptogramin B phenotype (cMLSB) and induced macrolide-lincosamide-streptogramin B phenotype (iMLSB). In addition, minimum inhibitory concentrations (MIC) of penicillin were determined for all isolates. Finally, possible existence of antibiotic resistance genes for erythromycin (ermTR, ermB and mefA/E) and for clindamycin (linB) were examined among isolates using PCR assay. Results: All 62 isolates were susceptible to penicillin, ampicillin, linezolid, cefazoline and vancomycin. However, 93.5% (n=58) of isolates showed an increased MIC to penicillin. The overall rate of erythromycin resistance was 35.5% (n=22). All erythromycin-resistant isolates displayed the M phenotype (100%, n=22). All three erythromycin resistance genes (i.e. ermTR, ermB and mefA/E) were found in erythromycin-resistant isolates. Conclusion: It was concluded that prescribing antibiotic without antibacterial susceptibility tests should be prevented because of the high prevalence of erythromycin-resistant GBS strains and the fact that erythromycin-resistant GBS strains has shown an increased MIC to penicillin, as the drug of choice for treating GBS infections.

  5. Survey of strain distribution and antibiotic resistance pattern of group B streptococci (Streptococcus agalactiae) isolated from clinical specimens

    PubMed Central

    Mousavi, Seyed Masoud; Nasaj, Mona; Hosseini, Seyed Mostafa; Arabestani, Mohammad Reza

    2016-01-01

    Aim: The aims of the present study were to determine the antibiotic susceptibility profils with particular emphasis on susceptible or resistant strains to macrolides and lincosamids antibiotics and to determine possible antibiotic resistance mechanisms occurring in group B streptococci (GBS) strains using PCR assay and disk diffusion method. Methods: A total of 62 clinical GBS strains were investigated. Antibacterial susceptibility testing was performed using the disk diffusion method and inducible resistance test for clindamycin by standard double disk diffusion or D-zone test for all isolates to differentiate macrolide resistance phenotype (M), constitutive macrolide-lincosamide-streptogramin B phenotype (cMLSB) and induced macrolide-lincosamide-streptogramin B phenotype (iMLSB). In addition, minimum inhibitory concentrations (MIC) of penicillin were determined for all isolates. Finally, possible existence of antibiotic resistance genes for erythromycin (ermTR, ermB and mefA/E) and for clindamycin (linB) were examined among isolates using PCR assay. Results: All 62 isolates were susceptible to penicillin, ampicillin, linezolid, cefazoline and vancomycin. However, 93.5% (n=58) of isolates showed an increased MIC to penicillin. The overall rate of erythromycin resistance was 35.5% (n=22). All erythromycin-resistant isolates displayed the M phenotype (100%, n=22). All three erythromycin resistance genes (i.e. ermTR, ermB and mefA/E) were found in erythromycin-resistant isolates. Conclusion: It was concluded that prescribing antibiotic without antibacterial susceptibility tests should be prevented because of the high prevalence of erythromycin-resistant GBS strains and the fact that erythromycin-resistant GBS strains has shown an increased MIC to penicillin, as the drug of choice for treating GBS infections. PMID:27648402

  6. 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

  7. Short communication: Streptococcus canis is able to establish a persistent udder infection in a dairy herd.

    PubMed

    Król, Jarosław; Twardoń, Jan; Mrowiec, Jacek; Podkowik, Magdalena; Dejneka, Grzegorz; Dębski, Bogdan; Nowicki, Tadeusz; Zalewski, Wojciech

    2015-10-01

    Bovine mastitis caused by Streptococcus canis is relatively rare. Consequently, many epidemiologic aspects of the infection, including factors that mediate crossing of host species barriers by the pathogen, infectiousness of the microorganism to the mammary gland, and the course of the disease within a herd, are still not elucidated. Therefore, the aim of the present study was to describe results of a 15-mo observation of subclinical Strep. canis mastitis on a dairy farm housing 76 lactating Holstein-Friesian cows. Upon 3 visits to the farm during a period between April 2013 and June 2014, Strep. canis was cultured from milk samples of 17 (22.4% of the herd), 7 (9.6%), and 8 (11.3%) cows, respectively. The isolates obtained were characterized phenotypically by means of the API Strep identification kit (bioMérieux, Marcy l'Etoile, France), as well as genetically by using random amplified polymorphic DNA and macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis. All strains displayed the same biochemical features, and the molecular methods revealed that the isolates belonged to a single clone or were very closely related. Results of the study indicate that Strep. canis is capable of causing intramammary infections of long duration, behaving in a contagious manner. Because a persistently infected cow may serve as the source of Strep. canis infection for other animals, effective control of this type of udder infection within a herd may require similar measures to those adopted in Streptococcus agalactiae eradication programs.

  8. [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

  9. Molecular Epidemiology and Genomics of Group A Streptococcus

    PubMed Central

    Bessen, Debra E.; McShan, W. Michael; Nguyen, Scott V.; Shetty, Amol; Agrawal, Sonia; Tettelin, Hervé

    2014-01-01

    Streptococcus pyogenes (group A streptococcus; GAS) is a strict human pathogen with a very high prevalence worldwide. This review highlights the genetic organization of the species and the important ecological considerations that impact its evolution. Recent advances are presented on the topics of molecular epidemiology, population biology, molecular basis for genetic change, genome structure and genetic flux, phylogenomics and closely related streptococcal species, and the long- and short-term evolution of GAS. The application of whole genome sequence data to addressing key biological questions is discussed. PMID:25460818

  10. Subtractive genomics approach to identify putative drug targets and identification of drug-like molecules for beta subunit of DNA polymerase III in Streptococcus species.

    PubMed

    Georrge, John J; Umrania, V V

    2012-07-01

    The prolonged use of the antibiotics over the years has transformed many organisms resistant to multiple drugs. This has made the field of drug discovery of vital importance in curing various infections and diseases. The drugs act by binding to a specific target protein of prime importance for the cell's survival. Streptococcus agalactiae, Streptococcus pneumoniae, and Streptococcus pyogenes are the few gram positive organisms that have developed resistance to drugs. It causes pneumonia, meningitis, pharyngitis, otitis media, sinusitis, bacteremia, pericarditis, and arthritis infections. The present study was carried out to identify potential drug targets and inhibitors for beta subunit of DNA polymerase III in these three Streptococcus species that might facilitate the discovery of novel drugs in near future. Various steps were adopted to find out novel drug targets. And finally 3D structure of DNA polymerase III subunit beta was modeled. The ligand library was generated from various databases to find the most suitable ligands. All the ligands were docked using Molegro Virtual Docker and the lead molecules were investigated for ADME and toxicity. PMID:22415782

  11. 21 CFR 526.1810 - Pirlimycin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... dairy cattle associated with Staphylococcus species such as Staphylococcus aureus and Streptococcus species such as Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis....

  12. 21 CFR 526.1810 - Pirlimycin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... dairy cattle associated with Staphylococcus species such as Staphylococcus aureus and Streptococcus species such as Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis....

  13. 21 CFR 526.1810 - Pirlimycin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... dairy cattle associated with Staphylococcus species such as Staphylococcus aureus and Streptococcus species such as Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis....

  14. 21 CFR 526.1810 - Pirlimycin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... associated with Staphylococcus species such as Staphylococcus aureus and Streptococcus species such as Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis. (3) Limitations. Milk taken...

  15. 21 CFR 526.1810 - Pirlimycin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... dairy cattle associated with Staphylococcus species such as Staphylococcus aureus and Streptococcus species such as Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis....

  16. Effect of xanthine derivates and dexamethasone on Streptococcus pneumoniae-stimulated production of tumor necrosis factor alpha, interleukin-1 beta (IL-1 beta), and IL-10 by human leukocytes.

    PubMed Central

    van Furth, A M; Seijmonsbergen, E M; Langermans, J A; van der Meide, P H; van Furth, R

    1995-01-01

    The present study concerns the release of the proinflammatory cytokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha and of the anti-inflammatory cytokine IL-10 by human leukocytes in whole blood during stimulation with Streptococcus pneumoniae and the effects of various xanthine derivates, i.e., pentoxifylline (PTX), caffeine, and theofylline, and of dexamethasone (DXM). All three xanthine derivates and DXM inhibited the release of tumor necrosis factor alpha, PTX being the most effective. PTX, theofylline, and DXM inhibited the release of IL-1 beta, but caffeine did not affect IL-1 beta release. The release of IL-10 was significantly reduced by PTX at 24 h and by caffeine at 48 h, but DXM increased the release of this cytokine. In sum, the results of this study demonstrate that DXM inhibits only the release of proinflammatory cytokines but not of the anti-inflammatory cytokine IL-10 by human leukocytes, while PTX is the most potent inhibitor of both proinflammatory and anti-inflammatory cytokines. PMID:8574830

  17. SecA Localization and SecA-Dependent Secretion Occurs at New Division Septa in Group B Streptococcus

    PubMed Central

    Brega, Sara; Caliot, Elise; Trieu-Cuot, Patrick; Dramsi, Shaynoor

    2013-01-01

    Exported proteins of Streptococcus agalactiae (GBS), which include proteins localized to the bacterial surface or secreted into the extracellular environment, are key players for commensal and pathogenic interactions in the mammalian host. These proteins are transported across the cytoplasmic membrane via the general SecA secretory pathway and those containing the so-called LPXTG sorting motif are covalently attached to the peptidoglycan by sortase A. How SecA, sortase A, and LPXTG proteins are spatially distributed in GBS is not known. In the close relative Streptococcus pyogenes, it was shown that presence of the YSIRKG/S motif (literally YSIRKX3Gx2S) in the signal peptide (SP) constitutes the targeting information for secretion at the septum. Here, using conventional and deconvolution immunofluorescence analyses, we have studied in GBS strain NEM316 the localization of SecA, SrtA, and the secreted protein Bsp whose signal peptide contains a canonical YSIRKG/S motif (YSLRKykfGlaS). Replacing the SP of Bsp with four other SPs containing or not the YSIRKG/S motif did not alter the localized secretion of Bsp at the equatorial ring. Our results indicate that secretion and cell wall-anchoring machineries are localized at the division septum. Cell wall- anchored proteins displayed polar (PilB, Gbs0791), punctuate (CspA) or uniform distribution (Alp2) on the bacterial surface. De novo secretion of Gbs0791 following trypsin treatment indicates that it is secreted at the septum, then redistributed along the lateral sides, and finally accumulated to the poles. We conclude that the ±YSIRK SP rule driving compartimentalized secretion is not true in S. agalactiae. PMID:23762438

  18. Diversity and Evolution of the Tn5801-tet(M)-Like Integrative and Conjugative Elements among Enterococcus, Streptococcus, and Staphylococcus

    PubMed Central

    León-Sampedro, Ricardo; Novais, Carla; Peixe, Luísa; Baquero, Fernando

    2016-01-01

    This work describes the diversity and evolution of Tn5801 among enterococci, staphylococci, and streptococci based on analysis of the 5,073 genomes of these bacterial groups available in gene databases. We also examined 610 isolates of Enterococcus (from 10 countries, 1987 to 2010) for the presence of this and other known CTn-tet(M) elements due to the scarcity of data about Tn5801 among enterococci. Genome location (by ICeu-I–pulsed-field gel electrophoresis [PFGE] hybridization/integration site identification), conjugation and fitness (by standard methods), Tn5801 characterization (by long-PCR mapping/sequencing), and clonality (by PFGE/multilocus sequence typing [MLST]) were studied. Twenty-three Tn5801 variants (17 unpublished) clustered in two groups, designated “A” (25 kb; n = 14; predominant in Staphylococcus aureus) and “B” (20 kb; n = 9; predominant in Streptococcus agalactiae). The percent GC content of the common backbone suggests a streptococcal origin of Tn5801 group B, with further acquisition of a 5-kb fragment that resulted in group A. Deep sequence analysis allowed identification of variants associated with clonal lineages of S. aureus (clonal complex 8 [CC8], sequence type 239 [ST239]), S. agalactiae (CC17), Enterococcus faecium (ST17/ST18), or Enterococcus faecalis (ST8), local variants, or variants located in different species and geographical areas. All Tn5801 elements were chromosomally located upstream of the guaA gene, which serves as an integration hot spot. Transferability was demonstrated only for Tn5801 type B among E. faecalis clonal backgrounds, which eventually harbored another Tn5801 copy. The study documents early acquisition of Tn5801 by Enterococcus, Staphylococcus, and Streptococcus. Clonal waves of these pathogens seem to have contributed to the geographical spread and local evolution of the transposon. Horizontal transfer, also demonstrated, could explain the variability observed, with the isolates often containing

  19. Diversity and Evolution of the Tn5801-tet(M)-Like Integrative and Conjugative Elements among Enterococcus, Streptococcus, and Staphylococcus.

    PubMed

    León-Sampedro, Ricardo; Novais, Carla; Peixe, Luísa; Baquero, Fernando; Coque, Teresa M

    2016-01-04

    This work describes the diversity and evolution of Tn5801 among enterococci, staphylococci, and streptococci based on analysis of the 5,073 genomes of these bacterial groups available in gene databases. We also examined 610 isolates of Enterococcus (from 10 countries, 1987 to 2010) for the presence of this and other known CTn-tet(M) elements due to the scarcity of data about Tn5801 among enterococci. Genome location (by ICeu-I-pulsed-field gel electrophoresis [PFGE] hybridization/integration site identification), conjugation and fitness (by standard methods), Tn5801 characterization (by long-PCR mapping/sequencing), and clonality (by PFGE/multilocus sequence typing [MLST]) were studied. Twenty-three Tn5801 variants (17 unpublished) clustered in two groups, designated "A" (25 kb; n = 14; predominant in Staphylococcus aureus) and "B" (20 kb; n = 9; predominant in Streptococcus agalactiae). The percent GC content of the common backbone suggests a streptococcal origin of Tn5801 group B, with further acquisition of a 5-kb fragment that resulted in group A. Deep sequence analysis allowed identification of variants associated with clonal lineages of S. aureus (clonal complex 8 [CC8], sequence type 239 [ST239]), S. agalactiae (CC17), Enterococcus faecium (ST17/ST18), or Enterococcus faecalis (ST8), local variants, or variants located in different species and geographical areas. All Tn5801 elements were chromosomally located upstream of the guaA gene, which serves as an integration hot spot. Transferability was demonstrated only for Tn5801 type B among E. faecalis clonal backgrounds, which eventually harbored another Tn5801 copy. The study documents early acquisition of Tn5801 by Enterococcus, Staphylococcus, and Streptococcus. Clonal waves of these pathogens seem to have contributed to the geographical spread and local evolution of the transposon. Horizontal transfer, also demonstrated, could explain the variability observed, with the isolates often containing sequences of

  20. Implication of sortase-dependent proteins of Streptococcus thermophilus in adhesion to human intestinal epithelial cell lines and bile salt tolerance.

    PubMed

    Kebouchi, Mounira; Galia, Wessam; Genay, Magali; Soligot, Claire; Lecomte, Xavier; Awussi, Ahoefa Ablavi; Perrin, Clarisse; Roux, Emeline; Dary-Mourot, Annie; Le Roux, Yves

    2016-04-01

    Streptococcus thermophilus (ST) is a lactic acid bacterium widely used in dairy industry and displays several properties which could be beneficial for host. The objective of this study was to investigate, in vitro, the implication of sortase A (SrtA) and sortase-dependent proteins (SDPs) in the adhesion of ST LMD-9 strain to intestinal epithelial cells (IECs) and resistance to bile salt mixture (BSM; taurocholoate, deoxycholate, and cholate). The effect of mutations in prtS (protease), mucBP (MUCin-Binding Protein), and srtA genes in ST LMD-9 in these mechanisms were examined. The HT29-MTX, HT29-CL.16E, and Caco-2 TC7 cell lines were used. HT29-MTX and HT29-CL.16E cells express different mucins found in the gastro intestinal tract; whereas, Caco-2 TC7 express cell surface proteins found in the small intestine. All mutants showed different adhesion profiles depending on cell lines. The mutation in genes srtA and mucBP leads to a significant decrease in LMD-9 adhesion capacity to Caco-2 TC7 cells. A mutation in mucBP gene has also shown a significant decrease in LMD-9 adhesion capacity to HT29-CL.16E cells. However, no difference was observed using HT29-MTX cells. Furthermore, ST LMD-9 and srtA mutant were resistant to BSM up to 3 mM. Contrariwise, no viable bacteria were detected for prtS and mucBP mutants at this concentration. Two conclusions could be drawn. First, SDPs could be involved in the LMD-9 adhesion depending on the cell lines indicating the importance of eukaryotic-cell surface components in adherence. Second, SDPs could contribute to resistance to bile salts probably by maintaining the cell membrane integrity. PMID:26820650

  1. Distribution and persistence of probiotic Streptococcus salivarius K12 in the human oral cavity as determined by real-time quantitative polymerase chain reaction.

    PubMed

    Horz, H-P; Meinelt, A; Houben, B; Conrads, G

    2007-04-01

    The bacteriocin producer Streptococcus salivarius K12 is used as a probiotic targeting the oral cavity, so our study aimed to assess whether its dispersal and persistence could be monitored using real-time quantitative polymerase chain reaction. To this end, we designed polymerase chain reaction primers and a hybridization probe specifically targeting salA, which encodes for the prepropeptide of salivaricin A. Using a single individual as our subject, we administered four lozenges of K12 Throat Guard per day over 3 days, then measured salA gene levels for 16 different oral sites at six different intervals over 35 days. Four samples each from gingival sulci and from teeth all remained negative. In contrast, in saliva and at all mucosal membranes K12 was detected, but with varying amounts and time profiles. Relatively high salA gene copy numbers, calibrated on the basis of colony-forming units, were seen on the tongue (maximum 4.6 x 10(4)/swab at day 4), in stimulated saliva (2.4 x 10(4)/ml, day 4) and on buccal membranes (1.3 x 10(4)/swab, day 8). K12 was present on both sides of the pharynx but asymmetrically in both quantity and duration. In conclusion, we have developed a real-time quantitative-polymerase chain reaction for counting S. salivarius K12 at various sites in the oral cavity. In the individual studied, K12 could be detected at the mucosal membranes for as long as 3 weeks, but with steadily decreasing numbers after day 8. Thus, K12 may have the potential to control oral bacterial infections only when the uptake is repeated frequently. PMID:17311636

  2. Phage 3396 from a Streptococcus dysgalactiae subsp. equisimilis pathovar may have its origins in streptococcus pyogenes.

    PubMed

    Davies, Mark R; McMillan, David J; Van Domselaar, Gary H; Jones, Malcolm K; Sriprakash, Kadaba S

    2007-04-01

    Streptococcus dysgalactiae subsp. equisimilis strains (group G streptococcus [GGS]) are largely defined as commensal organisms, which are closely related to the well-defined human pathogen, the group A streptococcus (GAS). While lateral gene transfers are emerging as a common theme in these species, little is known about the mechanisms and role of these transfers and their effect on the population structure of streptococci in nature. It is now becoming evident that bacteriophages are major contributors to the genotypic diversity of GAS and, consequently, are pivotal to the GAS strain structure. Furthermore, bacteriophages are strongly associated with altering the pathogenic potential of GAS. In contrast, little is know about phages from GGS and their role in the population dynamics of GGS. In this study we report the first complete genome sequence of a GGS phage, Phi3396. Exhibiting high homology to the GAS phage Phi315.1, the chimeric nature of Phi3396 is unraveled to reveal evidence of extensive ongoing genetic diversity and dissemination of streptococcal phages in nature. Furthermore, we expand on our recent findings to identify inducible Phi3396 homologues in GAS from a region of endemicity for GAS and GGS infection. Together, these findings provide new insights into not only the population structure of GGS but also the overall population structure of the streptococcal genus and the emergence of pathogenic variants.

  3. Maternal group B Streptococcus and the infant gut microbiota.

    PubMed

    Cassidy-Bushrow, A E; Sitarik, A; Levin, A M; Lynch, S V; Havstad, S; Ownby, D R; Johnson, C C; Wegienka, G

    2016-02-01

    Early patterns of gut colonization may predispose children to adult disease. Exposures in utero and during delivery are associated with the infant gut microbiome. Although ~35% of women carry group B strep (GBS; Streptococcus agalactiae) during pregnancy, it is unknown if GBS presence influences the infant gut microbiome. As part of a population-based, general risk birth cohort, stool specimens were collected from infant's diapers at research visits conducted at ~1 and 6 months of age. Using the Illumina MiSeq (San Diego, CA) platform, the V4 region of the bacterial 16S rRNA gene was sequenced. Infant gut bacterial community compositional differences by maternal GBS status were evaluated using permutational multivariate analysis of variance. Individual operational taxonomic units (OTUs) were tested using a zero-inflated negative binomial model. Data on maternal GBS and infant gut microbiota from either 1 (n=112) or 6-month-old stool (n=150) specimens was available on 262 maternal-child pairs. Eighty women (30.5%) were GBS+, of who 58 (72.5%) were given intrapartum antibiotics. After adjusting for maternal race, prenatal antifungal use and intrapartum antibiotics, maternal GBS status was statistically significantly associated with gut bacterial composition in the 6 month visit specimen (Canberra R 2=0.008, P=0.008; Unweighted UniFrac R 2=0.010, P=0.011). Individual OTU tests revealed that infants of GBS+ mothers were significantly enriched for specific members of the Clostridiaceae, Ruminococcoceae, and Enterococcaceae in the 6 month specimens compared with infants of GBS- mothers. Whether these taxonomic differences in infant gut microbiota at 6 months lead to differential predisposition for adult disease requires additional study. PMID:26264560

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

    PubMed Central

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

    2016-01-01

    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

  5. Use of the dynamic gastro-intestinal model TIM to explore the survival of the yogurt bacterium Streptococcus thermophilus and the metabolic activities induced in the simulated human gut.

    PubMed

    Uriot, Ophélie; Galia, Wessam; Awussi, Ahoefa Ablavi; Perrin, Clarisse; Denis, Sylvain; Chalancon, Sandrine; Lorson, Emilie; Poirson, Chantal; Junjua, Maira; Le Roux, Yves; Alric, Monique; Dary, Annie; Blanquet-Diot, Stéphanie; Roussel, Yvonne

    2016-02-01

    Streptococcus thermophilus, a lactic acid bacterium used to produce yogurts and cheeses is more and more considered for its potential probiotic properties. This implies that additional information should be obtained regarding its survival and metabolic activity in the human Gastro-Intestinal Tract (GIT). In this study, we screened 30 S. thermophilus strains for urease, small heat shock protein, and amino-acid decarboxylase functions which may play a role in survival in the upper part of the GIT. The survival kinetics of 4 strains was investigated using the TIM, a physiologically relevant in vitro dynamic gastric and small intestinal model. The three strains LMD9, PB18O and EBLST20 showed significantly higher survival than CNRZ21 in all digestive compartments of the TIM, which may be related to the presence of urease and heat shock protein functions. When LMD9 bacterial cells were delivered in a fermented milk formula, a significant improvement of survival in the TIM was observed compared to non-fermented milk. With the RIVET (Recombinase In Vivo Expression Technology) method applied to the LMD9 strain, a promoter located upstream of hisS, responsible for the histidyl-transfer RNA synthesis, was found to be specifically activated in the artificial stomach. The data generated on S. thermophilus survival and its adaptation capacities to the digestive tract are essential to establish a list of biomarkers useful for the selection of probiotic strains. PMID:26611166

  6. Use of the dynamic gastro-intestinal model TIM to explore the survival of the yogurt bacterium Streptococcus thermophilus and the metabolic activities induced in the simulated human gut.

    PubMed

    Uriot, Ophélie; Galia, Wessam; Awussi, Ahoefa Ablavi; Perrin, Clarisse; Denis, Sylvain; Chalancon, Sandrine; Lorson, Emilie; Poirson, Chantal; Junjua, Maira; Le Roux, Yves; Alric, Monique; Dary, Annie; Blanquet-Diot, Stéphanie; Roussel, Yvonne

    2016-02-01

    Streptococcus thermophilus, a lactic acid bacterium used to produce yogurts and cheeses is more and more considered for its potential probiotic properties. This implies that additional information should be obtained regarding its survival and metabolic activity in the human Gastro-Intestinal Tract (GIT). In this study, we screened 30 S. thermophilus strains for urease, small heat shock protein, and amino-acid decarboxylase functions which may play a role in survival in the upper part of the GIT. The survival kinetics of 4 strains was investigated using the TIM, a physiologically relevant in vitro dynamic gastric and small intestinal model. The three strains LMD9, PB18O and EBLST20 showed significantly higher survival than CNRZ21 in all digestive compartments of the TIM, which may be related to the presence of urease and heat shock protein functions. When LMD9 bacterial cells were delivered in a fermented milk formula, a significant improvement of survival in the TIM was observed compared to non-fermented milk. With the RIVET (Recombinase In Vivo Expression Technology) method applied to the LMD9 strain, a promoter located upstream of hisS, responsible for the histidyl-transfer RNA synthesis, was found to be specifically activated in the artificial stomach. The data generated on S. thermophilus survival and its adaptation capacities to the digestive tract are essential to establish a list of biomarkers useful for the selection of probiotic strains.

  7. Development and host compatibility of plasmids for two important ruminant pathogens, Mycoplasma bovis and Mycoplasma agalactiae.

    PubMed

    Sharma, Shukriti; Citti, Chistine; Sagné, Eveline; Marenda, Marc S; Markham, Philip F; Browning, Glenn F

    2015-01-01

    Mycoplasma bovis is a cause of pneumonia, mastitis, arthritis and otitis media in cattle throughout the world. However, despite its clinical significance, there is a paucity of tools to genetically manipulate it, impeding our capacity to further explore the molecular basis of its virulence. To address this limitation, we developed a series of homologous and heterologous replicable plasmids from M. bovis and M. agalactiae. The shortest replicable oriC plasmid based on the region downstream of dnaA in M. bovis was 247 bp and contained two DnaA boxes, while oriC plasmids based on the region downstream of dnaA in M. agalactiae strains 5632 and PG2 were 219 bp and 217 bp in length, respectively, and contained only a single DnaA box. The efficiency of transformation in M. bovis and M. agalactiae was inversely correlated with the size of the oriC region in the construct, and, in general, homologous oriC plasmids had a higher transformation efficiency than heterologous oriC plasmids. The larger pWholeoriC45 and pMM21-7 plasmids integrated into the genomic oriC region of M. bovis, while the smaller oriC plasmids remained extrachromosomal for up to 20 serial passages in selective media. Although specific gene disruptions were not be achieved in M. bovis in this study, the oriC plasmids developed here could still be useful as tools in complementation studies and for expression of exogenous genes in both M. bovis and M. agalactiae.

  8. An antagonist of the platelet-activating factor receptor inhibits adherence of both nontypeable Haemophilus influenzae and Streptococcus pneumoniae to cultured human bronchial epithelial cells exposed to cigarette smoke

    PubMed Central

    Shukla, Shakti D; Fairbairn, Rory L; Gell, David A; Latham, Roger D; Sohal, Sukhwinder S; Walters, Eugene H; O’Toole, Ronan F

    2016-01-01

    Background COPD is emerging as the third largest cause of human mortality worldwide after heart disease and stroke. Tobacco smoking, the primary risk factor for the development of COPD, induces increased expression of platelet-activating factor receptor (PAFr) in the lung epithelium. Nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae adhere to PAFr on the luminal surface of human respiratory tract epithelial cells. Objective To investigate PAFr as a potential drug target for the prevention of infections caused by the main bacterial drivers of acute exacerbations in COPD patients, NTHi and S. pneumoniae. Methods Human bronchial epithelial BEAS-2B cells were exposed to cigarette smoke extract (CSE). PAFr expression levels were determined using immunocytochemistry and quantitative polymerase chain reaction. The epithelial cells were challenged with either NTHi or S. pneumoniae labeled with fluorescein isothiocyanate, and bacterial adhesion was measured using immunofluorescence. The effect of a well-evaluated antagonist of PAFr, WEB-2086, on binding of the bacterial pathogens to BEAS-2B cells was then assessed. In silico studies of the tertiary structure of PAFr and the binding pocket for PAF and its antagonist WEB-2086 were undertaken. Results PAFr expression by bronchial epithelial cells was upregulated by CSE, and significantly associated with increased bacterial adhesion. WEB-2086 reduced the epithelial adhesion by both NTHi and S. pneumoniae to levels observed for non-CSE-exposed cells. Furthermore, it was nontoxic toward the bronchial epithelial cells. In silico analyses identified a binding pocket for PAF/WEB-2086 in the predicted PAFr structure. Conclusion WEB-2086 represents an innovative class of candidate drugs for inhibiting PAFr-dependent lung infections caused by the main bacterial drivers of smoking-related COPD. PMID:27524890

  9. Sheep primary cells as in vitro models to investigate Mycoplasma agalactiae host cell interactions.

    PubMed

    Hegde, Shrilakshmi; Gabriel, Cordula; Kragl, Martin; Chopra-Dewasthaly, Rohini

    2015-10-01

    Appropriate infection models are imperative for the understanding of pathogens like mycoplasmas that are known for their strict host and tissue specificity, and lack of suitable cell and small animal models has hindered pathogenicity studies. This is particularly true for the economically important group of ruminant mycoplasmas whose virulence factors need to be elucidated for designing effective intervention strategies. Mycoplasma agalactiae serves as a useful role model especially because it is phylogenetically very close to M. bovis and causes similar symptoms by as yet unknown mechanisms. Here, we successfully prepared and characterized four different primary sheep cell lines, namely the epithelial and stromal cells from the mammary gland and uterus, respectively. Using immunohistochemistry, we identified vimentin and cytokeratin as specific markers to confirm the typical cell phenotypes of these primary cells. Furthermore, M. agalactiae's consistent adhesion and invasion into these primary cells proves the reliability of these cell models. Mimicking natural infections, mammary epithelial and stromal cells showed higher invasion and adhesion rates compared to the uterine cells as also seen via double immunofluorescence staining. Altogether, we have generated promising in vitro cell models to study host-pathogen interactions of M. agalactiae and related ruminant pathogens in a more authentic manner.

  10. 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

  11. 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

  12. Streptococcus gallolyticus subsp. gallolyticus from human and animal origins: genetic diversity, antimicrobial susceptibility, and characterization of a vancomycin-resistant calf isolate carrying a vanA-Tn1546-like element.

    PubMed

    Romero-Hernández, Beatriz; Tedim, Ana P; Sánchez-Herrero, José Francisco; Librado, Pablo; Rozas, Julio; Muñoz, Gloria; Baquero, Fernando; Cantón, Rafael; Del Campo, Rosa

    2015-04-01

    The aim of this work was to characterize the antibiotic susceptibility and genetic diversity of 41 Streptococcus gallolyticus subsp. gallolyticus isolates: 18 isolates obtained from animals and 23 human clinical isolates. Antibiotic susceptibility was determined by the semiautomatic Wider system and genetic diversity by pulsed-field gel electrophoresis (PFGE) with SmaI. Animal isolates grouped separately in the PFGE analysis, but no statistical differences in antimicrobial resistance were found between the two groups. The LMG 17956 sequence type 28 (ST28) strain recovered from the feces of a calf exhibited high levels of resistance to vancomycin and teicoplanin (MIC, ≥256 mg/liter). Its glycopeptide resistance mechanism was characterized by Southern blot hybridization and a primer-walking strategy, and finally its genome, determined by whole-genome sequencing, was compared with four closely related S. gallolyticus subsp. gallolyticus genomes. Hybridization experiments demonstrated that a Tn1546-like element was integrated into the bacterial chromosome. In agreement with this finding, whole-genome sequencing confirmed a partial deletion of the vanY-vanZ region and partial duplication of the vanH gene. The comparative genomic analyses revealed that the LMG 17956 ST28 strain had acquired an unusually high number of transposable elements and had experienced extensive chromosomal rearrangements, as well as gene gain and loss events. In conclusion, S. gallolyticus subsp. gallolyticus isolates from animals seem to belong to lineages separate from those infecting humans. In addition, we report a glycopeptide-resistant isolate from a calf carrying a Tn1546-like element integrated into its chromosome.

  13. Streptococcus gallolyticus subsp. gallolyticus from Human and Animal Origins: Genetic Diversity, Antimicrobial Susceptibility, and Characterization of a Vancomycin-Resistant Calf Isolate Carrying a vanA-Tn1546-Like Element

    PubMed Central

    Romero-Hernández, Beatriz; Tedim, Ana P.; Sánchez-Herrero, José Francisco; Librado, Pablo; Rozas, Julio; Muñoz, Gloria; Baquero, Fernando; Cantón, Rafael

    2015-01-01

    The aim of this work was to characterize the antibiotic susceptibility and genetic diversity of 41 Streptococcus gallolyticus subsp. gallolyticus isolates: 18 isolates obtained from animals and 23 human clinical isolates. Antibiotic susceptibility was determined by the semiautomatic Wider system and genetic diversity by pulsed-field gel electrophoresis (PFGE) with SmaI. Animal isolates grouped separately in the PFGE analysis, but no statistical differences in antimicrobial resistance were found between the two groups. The LMG 17956 sequence type 28 (ST28) strain recovered from the feces of a calf exhibited high levels of resistance to vancomycin and teicoplanin (MIC, ≥256 mg/liter). Its glycopeptide resistance mechanism was characterized by Southern blot hybridization and a primer-walking strategy, and finally its genome, determined by whole-genome sequencing, was compared with four closely related S. gallolyticus subsp. gallolyticus genomes. Hybridization experiments demonstrated that a Tn1546-like element was integrated into the bacterial chromosome. In agreement with this finding, whole-genome sequencing confirmed a partial deletion of the vanY-vanZ region and partial duplication of the vanH gene. The comparative genomic analyses revealed that the LMG 17956 ST28 strain had acquired an unusually high number of transposable elements and had experienced extensive chromosomal rearrangements, as well as gene gain and loss events. In conclusion, S. gallolyticus subsp. gallolyticus isolates from animals seem to belong to lineages separate from those infecting humans. In addition, we report a glycopeptide-resistant isolate from a calf carrying a Tn1546-like element integrated into its chromosome. PMID:25605355

  14. Emergence of atypical Mycoplasma agalactiae strains harboring a new prophage and associated with an alpine wild ungulate mortality episode.

    PubMed

    Tardy, Florence; Baranowski, Eric; Nouvel, Laurent-Xavier; Mick, Virginie; Manso-Silvàn, Lucía; Thiaucourt, François; Thébault, Patricia; Breton, Marc; Sirand-Pugnet, Pascal; Blanchard, Alain; Garnier, Alexandre; Gibert, Philippe; Game, Yvette; Poumarat, François; Citti, Christine

    2012-07-01

    The bacterium Mycoplasma agalactiae is responsible for contagious agalactia (CA) in small domestic ruminants, a syndrome listed by the World Organization for Animal Health and responsible for severe damage to the dairy industry. Recently, we frequently isolated this pathogen from lung lesions of ibexes during a mortality episode in the French Alps. This situation was unusual in terms of host specificity and tissue tropism, raising the question of M. agalactiae emergence in wildlife. To address this issue, the ibex isolates were characterized using a combination of approaches that included antigenic profiles, molecular typing, optical mapping, and whole-genome sequencing. Genome analyses showed the presence of a new, large prophage containing 35 coding sequences (CDS) that was detected in most but not all ibex strains and has a homolog in Mycoplasma conjunctivae, a species causing keratoconjunctivitis in wild ungulates. This and the presence in all strains of large integrated conjugative elements suggested highly dynamic genomes. Nevertheless, M. agalactiae strains circulating in the ibex population were shown to be highly related, most likely originating from a single parental clone that has also spread to another wild ungulate species of the same geographical area, the chamois. These strains clearly differ from strains described in Europe so far, including those found nearby, before CA eradication a few years ago. While M. agalactiae pathogenicity in ibexes remains unclear, our data showed the emergence of atypical strains in Alpine wild ungulates, raising the question of a role for the wild fauna as a potential reservoir of pathogenic mycoplasmas. PMID:22522685

  15. Emergence of atypical Mycoplasma agalactiae strains harboring a new prophage and associated with an alpine wild ungulate mortality episode.

    PubMed

    Tardy, Florence; Baranowski, Eric; Nouvel, Laurent-Xavier; Mick, Virginie; Manso-Silvàn, Lucía; Thiaucourt, François; Thébault, Patricia; Breton, Marc; Sirand-Pugnet, Pascal; Blanchard, Alain; Garnier, Alexandre; Gibert, Philippe; Game, Yvette; Poumarat, François; Citti, Christine

    2012-07-01

    The bacterium Mycoplasma agalactiae is responsible for contagious agalactia (CA) in small domestic ruminants, a syndrome listed by the World Organization for Animal Health and responsible for severe damage to the dairy industry. Recently, we frequently isolated this pathogen from lung lesions of ibexes during a mortality episode in the French Alps. This situation was unusual in terms of host specificity and tissue tropism, raising the question of M. agalactiae emergence in wildlife. To address this issue, the ibex isolates were characterized using a combination of approaches that included antigenic profiles, molecular typing, optical mapping, and whole-genome sequencing. Genome analyses showed the presence of a new, large prophage containing 35 coding sequences (CDS) that was detected in most but not all ibex strains and has a homolog in Mycoplasma conjunctivae, a species causing keratoconjunctivitis in wild ungulates. This and the presence in all strains of large integrated conjugative elements suggested highly dynamic genomes. Nevertheless, M. agalactiae strains circulating in the ibex population were shown to be highly related, most likely originating from a single parental clone that has also spread to another wild ungulate species of the same geographical area, the chamois. These strains clearly differ from strains described in Europe so far, including those found nearby, before CA eradication a few years ago. While M. agalactiae pathogenicity in ibexes remains unclear, our data showed the emergence of atypical strains in Alpine wild ungulates, raising the question of a role for the wild fauna as a potential reservoir of pathogenic mycoplasmas.

  16. Simultaneous Identification of Potential Pathogenicity Factors of Mycoplasma agalactiae in the Natural Ovine Host by Negative Selection.

    PubMed

    Hegde, Shivanand; Hegde, Shrilakshmi; Zimmermann, Martina; Flöck, Martina; Spergser, Joachim; Rosengarten, Renate; Chopra-Dewasthaly, Rohini

    2015-07-01

    Mycoplasmas possess complex pathogenicity determinants that are largely unknown at the molecular level. Mycoplasma agalactiae serves as a useful model to study the molecular basis of mycoplasma pathogenicity. The generation and in vivo screening of a transposon mutant library of M. agalactiae were employed to unravel its host colonization factors. Tn4001mod mutants were sequenced using a novel sequencing method, and functionally heterogeneous pools containing 15 to 19 selected mutants were screened simultaneously through two successive cycles of sheep intramammary infections. A PCR-based negative selection method was employed to identify mutants that failed to colonize the udders and draining lymph nodes in the animals. A total of 14 different mutants found to be absent from ≥ 95% of samples were identified and subsequently verified via a second round of stringent confirmatory screening where 100% absence was considered attenuation. Using this criterion, seven mutants with insertions in genes MAG1050, MAG2540, MAG3390, uhpT, eutD, adhT, and MAG4460 were not recovered from any of the infected animals. Among the attenuated mutants, many contain disruptions in hypothetical genes, implying their previously unknown role in M. agalactiae pathogenicity. These data indicate the putative role of functionally different genes, including hypothetical ones, in the pathogenesis of M. agalactiae. Defining the precise functions of the identified genes is anticipated to increase our understanding of M. agalactiae infections and to develop successful intervention strategies against it. PMID:25916984

  17. Simultaneous Identification of Potential Pathogenicity Factors of Mycoplasma agalactiae in the Natural Ovine Host by Negative Selection

    PubMed Central

    Hegde, Shivanand; Hegde, Shrilakshmi; Zimmermann, Martina; Flöck, Martina; Spergser, Joachim; Rosengarten, Renate

    2015-01-01

    Mycoplasmas possess complex pathogenicity determinants that are largely unknown at the molecular level. Mycoplasma agalactiae serves as a useful model to study the molecular basis of mycoplasma pathogenicity. The generation and in vivo screening of a transposon mutant library of M. agalactiae were employed to unravel its host colonization factors. Tn4001mod mutants were sequenced using a novel sequencing method, and functionally heterogeneous pools containing 15 to 19 selected mutants were screened simultaneously through two successive cycles of sheep intramammary infections. A PCR-based negative selection method was employed to identify mutants that failed to colonize the udders and draining lymph nodes in the animals. A total of 14 different mutants found to be absent from ≥95% of samples were identified and subsequently verified via a second round of stringent confirmatory screening where 100% absence was considered attenuation. Using this criterion, seven mutants with insertions in genes MAG1050, MAG2540, MAG3390, uhpT, eutD, adhT, and MAG4460 were not recovered from any of the infected animals. Among the attenuated mutants, many contain disruptions in hypothetical genes, implying their previously unknown role in M. agalactiae pathogenicity. These data indicate the putative role of functionally different genes, including hypothetical ones, in the pathogenesis of M. agalactiae. Defining the precise functions of the identified genes is anticipated to increase our understanding of M. agalactiae infections and to develop successful intervention strategies against it. PMID:25916984

  18. Inactivation of bacterial pathogens in human milk by high-pressure processing.

    PubMed

    Viazis, S; Farkas, B E; Jaykus, L A

    2008-01-01

    Low-temperature, long-time (LTLT) pasteurization assures the safety of banked human milk; however, heat can destroy important nutritional biomolecules. High-pressure processing (HPP) shows promise as an alternative for pasteurization of breast milk. The purpose of this study was to investigate the efficacy of HPP for inactivation of selected bacterial pathogens in human milk. Human milk was inoculated with one of five pathogens (10(8) to 10(9) CFU/ml), while 0.1% peptone solution solutions with the same levels of each organism were used as controls. The samples were subjected to 400 MPa at 21 to 31 degrees C for 0 to 50 min or to 62.5 degrees C for 0 to 30 min (capillary tube method) to simulate LTLT pasteurization. Tryptic soy agar and selective media were used for enumeration. Traditional thermal pasteurization resulted in inactivation (> 7 log) of all pathogens within 10 min. In human milk and in peptone solution, a 6-log reduction was achieved after 30 min of HPP for Staphylococcus aureus ATCC 6538. After 30 min, S. aureus ATCC 25923 was reduced by 8 log and 6 log in human milk and peptone solution, respectively. Treatments of 4 and 7 min resulted in an 8-log inactivation of Streptococcus agalactiae ATCC 12927 in human milk and peptone solution, respectively, while Listeria monocytogenes ATCC 19115 required 2 min for an 8-log inactivation in human milk. Escherichia coli ATCC 25922 was inactivated by 8 log after 10 min in peptone solution and by 6 log after 30 min in human milk. These data suggest that HPP may be a promising alternative for pasteurization of human milk. Further research should evaluate the efficacy of HPP in the inactivation of relevant viral pathogens.

  19. 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.

  20. Human L-ficolin, a recognition molecule of the lectin activation pathway of complement, activates complement by binding to pneumolysin, the major toxin of Streptococcus pneumoniae.

    PubMed

    Ali, Youssif M; Kenawy, Hany I; Muhammad, Adnan; Sim, Robert B; Andrew, Peter W; Schwaeble, Wilhelm J

    2013-01-01

    The complement system is an essential component of the immune response, providing a critical line of defense against different pathogens including S. pneumoniae. Complement is activated via three distinct pathways: the classical (CP), the alternative (AP) and the lectin pathway (LP). The role of Pneumolysin (PLY), a bacterial toxin released by S. pneumoniae, in triggering complement activation has been studied in vitro. Our results demonstrate that in both human and mouse sera complement was activated via the CP, initiated by direct binding of even non-specific IgM and IgG3 to PLY. Absence of CP activity in C1q(-/-) mouse serum completely abolished any C3 deposition. However, C1q depleted human serum strongly opsonized PLY through abundant deposition of C3 activation products, indicating that the LP may have a vital role in activating the human complement system on PLY. We identified that human L-ficolin is the critical LP recognition molecule that drives LP activation on PLY, while all of the murine LP recognition components fail to bind and activate complement on PLY. This work elucidates the detailed interactions between PLY and complement and shows for the first time a specific role of the LP in PLY-mediated complement activation in human serum.

  1. Evolution and Diversity of the Antimicrobial Resistance Associated Mobilome in Streptococcus suis: A Probable Mobile Genetic Elements Reservoir for Other Streptococci

    PubMed Central

    Huang, Jinhu; Ma, Jiale; Shang, Kexin; Hu, Xiao; Liang, Yuan; Li, Daiwei; Wu, Zuowei; Dai, Lei; Chen, Li; Wang, Liping

    2016-01-01

    Streptococcus suis is a previously neglected, newly emerging multidrug-resistant zoonotic pathogen. Mobile genetic elements (MGEs) play a key role in intra- and interspecies horizontal transfer of antimicrobial resistance (AMR) determinants. Although, previous studies showed the presence of several MGEs, a comprehensive analysis of AMR-associated mobilome as well as their interaction and evolution has not been performed. In this study, we presented the AMR-associated mobilome and their insertion hotspots in S. suis. Integrative conjugative elements (ICEs), prophages and tandem MGEs were located at different insertion sites, while 86% of the AMR-associated MGEs were inserted at rplL and rum loci. Comprehensive analysis of insertions at rplL and rum loci among four pathogenic Streptococcus species (Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and S. suis) revealed the existence of different groups of MGEs, including Tn5252, ICESp1108, and TnGBS2 groups ICEs, Φm46.1 group prophage, ICE_ICE and ICE_prophage tandem MGEs. Comparative ICE genomics of ICESa2603 family revealed that module exchange and acquisition/deletion were the main mechanisms in MGEs' expansion and evolution. Furthermore, the observation of tandem MGEs reflected a novel mechanism for MGE diversity. Moreover, an in vitro competition assay showed no visible fitness cost was observed between different MGE-carrying isolates and a conjugation assay revealed the transferability of ICESa2603 family of ICEs. Our statistics further indicated that the prevalence and diversity of MGEs in S. suis is much greater than in other three species which prompted our hypothesis that S. suis is probably a MGEs reservoir for other streptococci. In conclusion, our results showed that acquisition of MGEs confers S. suis not only its capability as a multidrug resistance pathogen, but also represents a paradigm to study the modular evolution and matryoshkas of MGEs. PMID:27774436

  2. Complete Genome Sequence of the Clinical Streptococcus salivarius Strain CCHSS3 ▿

    PubMed Central

    Delorme, Christine; Guédon, Eric; Pons, Nicolas; Cruaud, Corinne; Couloux, Arnaud; Loux, Valentin; Chiapello, Hélène; Poyart, Claire; Gautier, Céline; Sanchez, Nicolas; Almeida, Mathieu; Kennedy, Sean P.; Ehrlich, S. Dusko; Gibrat, Jean-François; Wincker, Patrick; Renault, Pierre

    2011-01-01

    Streptococcus salivarius is a commensal species commonly found in the human oral cavity and digestive tract, although it is also associated with human infections such as meningitis, endocarditis, and bacteremia. Here, we report the complete sequence of S. salivarius strain CCHSS3, isolated from human blood. PMID:21742894

  3. Complete genome sequence of the clinical Streptococcus salivarius strain CCHSS3.

    PubMed

    Delorme, Christine; Guédon, Eric; Pons, Nicolas; Cruaud, Corinne; Couloux, Arnaud; Loux, Valentin; Chiapello, Hélène; Poyart, Claire; Gautier, Céline; Sanchez, Nicolas; Almeida, Mathieu; Kennedy, Sean P; Ehrlich, S Dusko; Gibrat, Jean-François; Wincker, Patrick; Renault, Pierre

    2011-09-01

    Streptococcus salivarius is a commensal species commonly found in the human oral cavity and digestive tract, although it is also associated with human infections such as meningitis, endocarditis, and bacteremia. Here, we report the complete sequence of S. salivarius strain CCHSS3, isolated from human blood. PMID:21742894

  4. Liquid–liquid diffusion crystallization improves the X-ray diffraction of EndoS, an endo-β-N-acetyl­glucosaminidase from Streptococcus pyogenes with activity on human IgG

    PubMed Central

    Trastoy, Beatriz; Lomino, Joseph V.; Wang, Lai-Xi; Sundberg, Eric J.

    2013-01-01

    Endoglycosidase S (EndoS) is an enzyme secreted by Streptococcus pyogenes that specifically hydrolyzes the β-1,4-di-N-acetylchitobiose core glycan on immunoglobulin G (IgG) antibodies. One of the most common human pathogens and the cause of group A streptococcal infections, S. pyogenes secretes EndoS in order to evade the host immune system by rendering IgG effector mechanisms dysfunctional. On account of its specificity for IgG, EndoS has also been used extensively for chemoenzymatic synthesis of homogeneous IgG glycoprotein preparations and is being developed as a novel therapeutic for a wide range of autoimmune diseases. The structural basis of its enzymatic activity and substrate specificity, however, remains unknown. Here, the purification and crystallization of EndoS are reported. Using traditional hanging-drop and sitting-drop vapor-diffusion crystallization, crystals of EndoS were grown that diffracted to a maximum of 3.5 Å resolution but suffered from severe anisotropy, the data from which could only be reasonably processed to 7.5 Å resolution. When EndoS was crystallized by liquid–liquid diffusion, it was possible to grow crystals with a different space group to those obtained by vapor diffusion. Crystals of wild-type endoglycosidase and glycosynthase constructs of EndoS grown by liquid–liquid diffusion diffracted to 2.6 and 1.9 Å resolution, respectively, with a greatly diminished anisotropy. Despite extensive efforts, the failure to reproduce these liquid–liquid diffusion-grown crystals by vapor diffusion suggests that these crystallization methods each sample a distinct crystallization space. PMID:24316841

  5. Liquid-liquid diffusion crystallization improves the X-ray diffraction of EndoS, an endo-β-N-acetylglucosaminidase from Streptococcus pyogenes with activity on human IgG.

    PubMed

    Trastoy, Beatriz; Lomino, Joseph V; Wang, Lai Xi; Sundberg, Eric J

    2013-12-01

    Endoglycosidase S (EndoS) is an enzyme secreted by Streptococcus pyogenes that specifically hydrolyzes the β-1,4-di-N-acetylchitobiose core glycan on immunoglobulin G (IgG) antibodies. One of the most common human pathogens and the cause of group A streptococcal infections, S. pyogenes secretes EndoS in order to evade the host immune system by rendering IgG effector mechanisms dysfunctional. On account of its specificity for IgG, EndoS has also been used extensively for chemoenzymatic synthesis of homogeneous IgG glycoprotein preparations and is being developed as a novel therapeutic for a wide range of autoimmune diseases. The structural basis of its enzymatic activity and substrate specificity, however, remains unknown. Here, the purification and crystallization of EndoS are reported. Using traditional hanging-drop and sitting-drop vapor-diffusion crystallization, crystals of EndoS were grown that diffracted to a maximum of 3.5 Å resolution but suffered from severe anisotropy, the data from which could only be reasonably processed to 7.5 Å resolution. When EndoS was crystallized by liquid-liquid diffusion, it was possible to grow crystals with a different space group to those obtained by vapor diffusion. Crystals of wild-type endoglycosidase and glycosynthase constructs of EndoS grown by liquid-liquid diffusion diffracted to 2.6 and 1.9 Å resolution, respectively, with a greatly diminished anisotropy. Despite extensive efforts, the failure to reproduce these liquid-liquid diffusion-grown crystals by vapor diffusion suggests that these crystallization methods each sample a distinct crystallization space.

  6. Flow cytometric method for the assessment of the minimal inhibitory concentrations of antibacterial agents to Mycoplasma agalactiae.

    PubMed

    Assunção, Patrícia; Antunes, Nuno T; Rosales, Ruben S; de la Fe, Christian; Poveda, Carlos; Poveda, José B; Davey, Hazel M

    2006-10-01

    In this study, flow cytometry was evaluated for the determination of the minimal inhibitory concentrations (MIC) of seven antibacterial agents (enrofloxacin, ciprofloxacin, gentamicin, streptomycin, chloramphenicol, oxytetracycline, and tylosin) on Mycoplasma (M.) agalactiae. Flow cytometry was able to detect M. agalactiae inhibition from 6 h postincubation, although it seems that definitive MIC values determined by flow cytometry were only possible at 12-h postincubation. However, the results obtained by the traditional method were only obtained at 24 h, when a visible change in the medium had occurred. At 24 h, both methods gave the same result for six antibacterial agents (enrofloxacin, ciprofloxacin, gentamicin, streptomycin, chloramphenicol, and oxytetracycline); whereas flow cytometry gave slightly higher MIC for tylosin. This was attributed to the fact that the M. agalactiae growth that had occurred in the tubes containing tylosin was not enough to visibly change the color of the medium. Futhermore, flow cytometry detected that inhibitory concentrations of oxytetracycline, chloramphenicol, and tylosin as judged at 24 h were not able to inhibit the M. agalactiae growth after 48 h. MIC values of enrofloxacin and ciprofloxacin were sufficient only to maintain the total counts per milliliter throughout the time matched samples, whereas higher concentrations of theses antibacterial agents reduced the total counts per milliliter over the course of the experiment. The main advantage of the flow cytometric method is that MIC results for M. agalactiae can be obtained in a shorter time than is possible with the traditional method. The method presented makes identification of resistant populations of M. agalactiae possible and, unlike the traditional method, allows the effect of each antibacterial agent to be determined in real-time at the single-cell level. PMID:16998868

  7. Biofilm formation enhances fomite survival of Streptococcus pneumoniae and Streptococcus pyogenes.

    PubMed

    Marks, Laura R; Reddinger, Ryan M; Hakansson, Anders P

    2014-03-01

    Both Streptococcus pyogenes and Streptococcus pneumoniae are widely thought to rapidly die outside the human host, losing infectivity following desiccation in the environment. However, to date, all literature investigating the infectivity of desiccated streptococci has used broth-grown, planktonic populations. In this study, we examined the impact of biofilm formation on environmental survival of clinical and laboratory isolates of S. pyogenes and S. pneumoniae as both organisms are thought to colonize the human host as biofilms. Results clearly demonstrate that while planktonic cells that are desiccated rapidly lose viability both on hands and abiotic surfaces, such as plastic, biofilm bacteria remain viable over extended periods of time outside the host and remain infectious in a murine colonization model. To explore the level and extent of streptococcal fomite contamination that children might be exposed to naturally, direct bacteriologic cultures of items in a day care center were conducted, which demonstrated high levels of viable streptococci of both species. These findings raise the possibility that streptococci may survive in the environment and be transferred from person to person via fomites contaminated with oropharyngeal secretions containing biofilm streptococci.

  8. Impact of immunization against SpyCEP during invasive disease with two streptococcal species: Streptococcus pyogenes and Streptococcus equi

    PubMed Central

    Turner, Claire E.; Kurupati, Prathiba; Wiles, Siouxsie; Edwards, Robert J.; Sriskandan, Shiranee

    2009-01-01

    Currently there is no licensed vaccine against the human pathogen Streptococcus pyogenes. The highly conserved IL-8 cleaving S. pyogenes cell envelope proteinase SpyCEP is surface expressed and is a potential vaccine candidate. A recombinant N-terminal part of SpyCEP (CEP) was expressed and purified. AntiCEP antibodies were found to neutralize the IL-8 cleaving activity of SpyCEP. CEP-immunized mice had reduced bacterial dissemination from focal S. pyogenes intramuscular infection and intranasal infection. We also identified a functional SpyCEP-homolog protease SeCEP, expressed by the equine pathogen Streptococcus equi, which was able to cleave both human and equine IL-8. CEP-immunized mice also demonstrated reduced bacterial dissemination from S. equi intramuscular infection. Therefore immunization against SpyCEP may provide protection against other streptococci species with homologous proteases. PMID:19563892

  9. 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

  10. 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.

  11. On the agalactia post partum in the sow. A clinical study.

    PubMed

    Hermansson, I; Einarsson, S; Larsson, K; Bäckström, L

    1978-11-01

    The purpose of the present investigation was to study the clinical symptoms of agalactic sows post partum in randomly selected swine herds. The study comprised 71 sows affected with agalactia post partum and 71 healthy sows from the same herds used as controls. Average morbidity of the disease in these 50 herds, consisting of an average of 25 sows, was 12.8%. Sixty-three per cent of the agalactic sows were affected within one day after farrowing. There was no difference in gestation length between healthy sows and agalactic sows. The body temperature was significantly higher for affected than for healthy sows. Mastitis was diagnosed in 35 out of 71 agalactic sows. The criteria for mastitis were swelling and herdening of one or several udder glands. Vaginal discharge was recorded for affected sows (55/57) as well as for healthy sows (51/58) and is therefore not significantly associated with agalactia. The temperament of the agalactic sows was moderately or severely affected in 62 out of 71 agalactic sows. Constipation was recorded for 13/59 agalactic sows and for 3/57 normal sows. The agalactic sows had significantly higher number of piglets per litter at birth while the litter size was higher for healthy sows at weaning. Numerically, more sows were culled among agalactic sows (16/48) than among normal sows (6/42). Moreover, sows affected with agalactia at the previous parturition were more inclined to meet with the disease at the next parturition. Further studies comprising large groups of animals are, however, necessary for evaluation of this question.

  12. 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.

  13. 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

  14. GLYOXYLATE FERMENTATION BY STREPTOCOCCUS ALLANTOICUS

    PubMed Central

    Valentine, R. C.; Drucker, H.; Wolfe, R. S.

    1964-01-01

    Valentine, R. C. (University of Illinois, Urbana), H. Drucker, and R. S. Wolfe. Glyoxylate fermentation by Streptococcus allantoicus. J. Bacteriol. 87:241–246. 1964.—Extracts of Streptococcus allantoicus were found to degrade glyoxylate, yielding tartronic semialdehyde and CO2. Tartronic semialdehyde was prepared chemically, and its properties were compared with the enzymatic product: reduction by sodium borohydride yielded glycerate; heating at 100 C yielded glycolaldehyde and CO2; autoxidation yielded mesoxalic semialdehyde; periodate oxidation yielded glyoxylate and a compound presumed to be formate. Tartronic semialdehyde reductase was present in extracts of S. allantoicus and in a species of Pseudomonas grown on allantoin. A scheme for the synthesis of acetate from glyoxylate by S. allantoicus is discussed. PMID:14151040

  15. Mucosal Immunization with an Unadjuvanted Vaccine That Targets Streptococcus pneumoniae PspA to Human Fcγ Receptor Type I Protects against Pneumococcal Infection through Complement- and Lactoferrin-Mediated Bactericidal Activity

    PubMed Central

    Bitsaktsis, Constantine; Iglesias, Bibiana V.; Li, Ying; Colino, Jesus; Snapper, Clifford M.; Hollingshead, Susan K.; Pham, Giang; Gosselin, Diane R.

    2012-01-01

    Targeting an antigen to Fc receptors (FcR) can enhance the immune response to the antigen in the absence of adjuvant. Furthermore, we recently demonstrated that intranasal immunization with an FcγR-targeted antigen enhances protection against a category A intracellular mucosal pathogen, Francisella tularensis. To determine if a similar strategy could be applied to the important pathogen Streptococcus pneumoniae, we used an improved mucosal FcR-targeting strategy that specifically targets human FcγR type I (hFcγRI). A humanized single-chain antibody component in which the variable domain binds to hFcγRI [anti-hFcγRI (H22)] was linked in a fusion protein with the pneumococcal surface protein A (PspA). PspA is known to elicit protection against pneumococcal sepsis, carriage, and pneumonia in mouse models when administered with adjuvants. Anti-hFcγRI-PspA or recombinant PspA (rPspA) alone was used to intranasally immunize wild-type (WT) and hFcγRI transgenic (Tg) mice in the absence of adjuvant. The hFcγRI Tg mice receiving anti-hFcγRI-PspA exhibited elevated S. pneumoniae-specific IgA, IgG2c, and IgG1 antibodies in serum and bronchoalveolar lavage fluid. Neither immunogen was effective in protecting WT mice in the absence of adjuvant, but when PspA was targeted to hFcγRI as the anti-hFcγRI-PspA fusion, enhanced protection against lethal S. pneumoniae challenge was observed in the hFcγRI Tg mice compared to mice given nontargeted rPspA alone. Immune sera from the anti-hFcγRI-PspA-immunized Tg mice showed enhanced complement C3 deposition on bacterial surfaces, and protection was dependent upon an active complement system. Immune serum also showed an enhanced bactericidal activity directed against S. pneumoniae that appears to be lactoferrin mediated. PMID:22158740

  16. Immunochromatographic detection of the group B streptococcus antigen from enrichment cultures.

    PubMed

    Matsui, Hidehito; Kimura, Juri; Higashide, Masato; Takeuchi, Yoshio; Okue, Kuniyuki; Cui, Longzhu; Nakae, Taiji; Sunakawa, Keisuke; Hanaki, Hideaki

    2013-09-01

    Group B Streptococcus (GBS; Streptococcus agalactiae) is a leading cause of serious neonatal infections. The Centers for Disease Control and Prevention recommends GBS screening for all pregnant women during the 35th to 37th weeks of gestation. Although GBS screening has been performed mainly by the culture-based method, it takes several days to obtain a reliable result. In this study, we developed a rapid immunochromatographic test (ICT) for the detection of GBS-specific surface immunogenic protein in 15 min using an overnight enrichment culture. The ICT was prepared using two anti-Sip monoclonal antibodies. This ICT was able to detect recombinant Sip levels of 0.5 ng/ml, or about 10(6) CFU/ml of GBS cells, in tests with 9 GBS strains of different serotypes. The cross-reactivity test using 26 species of microorganism showed no detectable false-positive result. Reactivity of the ICT with 229 GBS strains showed one false-negative result that was attributable to the production of truncated Sip. Among 260 enrichment cultures of vaginal swabs, 17 produced red to orange pigments in Granada medium, and they were all GBS and Sip positive. Among 219 pigment-negative cultures, 12 were GBS positive and 10 were Sip positive. Two Sip-negative cultures contained GBS cells below the limit of detection by the ICT. Among 207 GBS-negative cultures, only one was Sip positive, which was attributable to GBS cell debris. Thus, the sensitivity and specificity of the ICT appeared to be 93.1% and 99.6%, respectively. The newly developed ICT is readily applicable to clinical use in the detection of GBS.

  17. Immunochromatographic Detection of the Group B Streptococcus Antigen from Enrichment Cultures

    PubMed Central

    Matsui, Hidehito; Kimura, Juri; Higashide, Masato; Takeuchi, Yoshio; Okue, Kuniyuki; Cui, Longzhu; Nakae, Taiji; Sunakawa, Keisuke

    2013-01-01

    Group B Streptococcus (GBS; Streptococcus agalactiae) is a leading cause of serious neonatal infections. The Centers for Disease Control and Prevention recommends GBS screening for all pregnant women during the 35th to 37th weeks of gestation. Although GBS screening has been performed mainly by the culture-based method, it takes several days to obtain a reliable result. In this study, we developed a rapid immunochromatographic test (ICT) for the detection of GBS-specific surface immunogenic protein in 15 min using an overnight enrichment culture. The ICT was prepared using two anti-Sip monoclonal antibodies. This ICT was able to detect recombinant Sip levels of 0.5 ng/ml, or about 106 CFU/ml of GBS cells, in tests with 9 GBS strains of different serotypes. The cross-reactivity test using 26 species of microorganism showed no detectable false-positive result. Reactivity of the ICT with 229 GBS strains showed one false-negative result that was attributable to the production of truncated Sip. Among 260 enrichment cultures of vaginal swabs, 17 produced red to orange pigments in Granada medium, and they were all GBS and Sip positive. Among 219 pigment-negative cultures, 12 were GBS positive and 10 were Sip positive. Two Sip-negative cultures contained GBS cells below the limit of detection by the ICT. Among 207 GBS-negative cultures, only one was Sip positive, which was attributable to GBS cell debris. Thus, the sensitivity and specificity of the ICT appeared to be 93.1% and 99.6%, respectively. The newly developed ICT is readily applicable to clinical use in the detection of GBS. PMID:23825191

  18. Short communication: Streptococcus canis is able to establish a persistent udder infection in a dairy herd.

    PubMed

    Król, Jarosław; Twardoń, Jan; Mrowiec, Jacek; Podkowik, Magdalena; Dejneka, Grzegorz; Dębski, Bogdan; Nowicki, Tadeusz; Zalewski, Wojciech

    2015-10-01

    Bovine mastitis caused by Streptococcus canis is relatively rare. Consequently, many epidemiologic aspects of the infection, including factors that mediate crossing of host species barriers by the pathogen, infectiousness of the microorganism to the mammary gland, and the course of the disease within a herd, are still not elucidated. Therefore, the aim of the present study was to describe results of a 15-mo observation of subclinical Strep. canis mastitis on a dairy farm housing 76 lactating Holstein-Friesian cows. Upon 3 visits to the farm during a period between April 2013 and June 2014, Strep. canis was cultured from milk samples of 17 (22.4% of the herd), 7 (9.6%), and 8 (11.3%) cows, respectively. The isolates obtained were characterized phenotypically by means of the API Strep identification kit (bioMérieux, Marcy l'Etoile, France), as well as genetically by using random amplified polymorphic DNA and macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis. All strains displayed the same biochemical features, and the molecular methods revealed that the isolates belonged to a single clone or were very closely related. Results of the study indicate that Strep. canis is capable of causing intramammary infections of long duration, behaving in a contagious manner. Because a persistently infected cow may serve as the source of Strep. canis infection for other animals, effective control of this type of udder infection within a herd may require similar measures to those adopted in Streptococcus agalactiae eradication programs. PMID:26233445

  19. 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.

  20. Characterization of salivary alpha-amylase binding to Streptococcus sanguis

    SciTech Connect

    Scannapieco, F.A.; Bergey, E.J.; Reddy, M.S.; Levine, M.J. )

    1989-09-01

    The purpose of this study was to identify the major salivary components which interact with oral bacteria and to determine the mechanism(s) responsible for their binding to the bacterial surface. Strains of Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, and Actinomyces viscosus were incubated for 2 h in freshly collected human submandibular-sublingual saliva (HSMSL) or parotid saliva (HPS), and bound salivary components were eluted with 2% sodium dodecyl sulfate. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western transfer, alpha-amylase was the prominent salivary component eluted from S. sanguis. Studies with {sup 125}I-labeled HSMSL or {sup 125}I-labeled HPS also demonstrated a component with an electrophoretic mobility identical to that of alpha-amylase which bound to S. sanguis. Purified alpha-amylase from human parotid saliva was radiolabeled and found to bind to strains of S. sanguis genotypes 1 and 3 and S. mitis genotype 2, but not to strains of other species of oral bacteria. Binding of ({sup 125}I)alpha-amylase to streptococci was saturable, calcium independent, and inhibitable by excess unlabeled alpha-amylases from a variety of sources, but not by secretory immunoglobulin A and the proline-rich glycoprotein from HPS. Reduced and alkylated alpha-amylase lost enzymatic and bacterial binding activities. Binding was inhibited by incubation with maltotriose, maltooligosaccharides, limit dextrins, and starch.

  1. One More Disguise in the Stealth Behavior of Streptococcus pyogenes.

    PubMed

    Fischetti, Vincent A; Dale, James B

    2016-05-17

    The ability to hide in the animal kingdom is essential for survival; the same is true for bacteria. Streptococcus pyogenes is considered one of the more successful stealth bacteria in its production of a hyaluronic acid capsule that is chemically identical to the hyaluronic acid lining human joints. It has also acquired the capacity to enter eukaryotic cells to avoid the onslaught of the host's immune defenses, as well as drugs. From this intracellular vantage point, it may remain dormant from days to weeks, only to cause disease again at a later time, perhaps causing a relapse in a drug-treated patient. We now learn that it is able to enter macrophages as well, enabling the Streptococcus to use this "Trojan horse" approach to be transported to distant sites in the body.

  2. One More Disguise in the Stealth Behavior of Streptococcus pyogenes

    PubMed Central

    Dale, James B.

    2016-01-01

    ABSTRACT The ability to hide in the animal kingdom is essential for survival; the same is true for bacteria. Streptococcus pyogenes is considered one of the more successful stealth bacteria in its production of a hyaluronic acid capsule that is chemically identical to the hyaluronic acid lining human joints. It has also acquired the capacity to enter eukaryotic cells to avoid the onslaught of the host’s immune defenses, as well as drugs. From this intracellular vantage point, it may remain dormant from days to weeks, only to cause disease again at a later time, perhaps causing a relapse in a drug-treated patient. We now learn that it is able to enter macrophages as well, enabling the Streptococcus to use this “Trojan horse” approach to be transported to distant sites in the body. PMID:27190219

  3. Epidemiology of Mycoplasma agalactiae infection in free-ranging Spanish ibex (Capra pyrenaica) in Andalusia, southern Spain.

    PubMed

    Verbisck-Bucker, G; González-Candela, M; Galián, J; Cubero-Pablo, M J; Martín-Atance, P; León-Vizcaíno, L

    2008-04-01

    Mycoplasma agalactiae is the main causal agent of contagious agalactia syndrome in Spain. It is a severe disease of small ruminants, endemic in Mediterranean countries, that is characterized by mastitis, arthritis, and keratoconjunctivitis. This paper investigates the temporal, spatial, and host-related factors in the distribution of M. agalactiae infection from October 1996 to November 1998 and March 2002 to May 2003 in Spanish ibex (Capra pyrenaica) populations from Andalusia, in southern Spain. The predisposing factors to infection among previously selected factors (year of sampling, climatic season, geographic origin according to province, mountain range and metapopulation, sex, year of life, presence of scabies, and phase of the reproductive cycle) were established. We collected conjunctival and ear-canal swabs from 411 free-ranging ibexes. The frequency of infected ibexes was 11.2%. The peak frequency of infection occurred in 1998 and in summer. Granada was the province with greatest risk (odds ratio = 2.6) of carriers (18.8% infected). The predisposing factors were sex (females), age (young animals), and metapopulation (Sierra Nevada). We identified a higher number of infected ibexes in the metapopulation "Sierra Nevada" (34/ 256) and significant differences among the three established metapopulations (P<0.01). Mycoplasma agalactiae infection represents a risk for population density and maintenance of these wild populations; infections can result in blindness, malnutrition, and polyarthritis leading to numerous deaths. PMID:18436669

  4. Electrophoretic Analysis of Indian Isolates of Mycoplasma agalactiae and Mycoplasma bovis by SDS-PAGE and Immunoblotting

    PubMed Central

    Kumar, Amit; Srivastava, N. C.; Singh, V. P.; Sunder, Jai

    2014-01-01

    Mycoplasma agalactiae and Mycoplasma bovis both are responsible for respiratory conditions in sheep and goats. M. agalactiae is a major pathogen of sheep and goats and accounts for almost 90% of outbreaks of contagious agalactia syndrome in goats and almost 100% in sheep. On the basis of clinical signs and cultural, morphological, and biochemical characterization it is almost impossible to differentiate between both the species. Moreover, due to presence of genomic and proteomic similarity most of the time routine diagnostic tests fail to differentiate between them. Hence the present study was conducted to find out the protein profile of isolates of both the species by SDS-PAGE and to find out the cross-reacting as well as differentiating immunogenic proteins by Immunoblotting, which can be of immunoprophylactic as well as diagnostic values. The study revealed 6-7 major immunogenic cross-reactive proteins with the presence of two important non-cross-reacting species specific polypeptides particularly 25.50 and 24.54 kDa in M. agalactiae and M. bovis, respectively, that might be of diagnostic values. PMID:24808973

  5. Epidemiology of Mycoplasma agalactiae infection in free-ranging Spanish ibex (Capra pyrenaica) in Andalusia, southern Spain.

    PubMed

    Verbisck-Bucker, G; González-Candela, M; Galián, J; Cubero-Pablo, M J; Martín-Atance, P; León-Vizcaíno, L

    2008-04-01

    Mycoplasma agalactiae is the main causal agent of contagious agalactia syndrome in Spain. It is a severe disease of small ruminants, endemic in Mediterranean countries, that is characterized by mastitis, arthritis, and keratoconjunctivitis. This paper investigates the temporal, spatial, and host-related factors in the distribution of M. agalactiae infection from October 1996 to November 1998 and March 2002 to May 2003 in Spanish ibex (Capra pyrenaica) populations from Andalusia, in southern Spain. The predisposing factors to infection among previously selected factors (year of sampling, climatic season, geographic origin according to province, mountain range and metapopulation, sex, year of life, presence of scabies, and phase of the reproductive cycle) were established. We collected conjunctival and ear-canal swabs from 411 free-ranging ibexes. The frequency of infected ibexes was 11.2%. The peak frequency of infection occurred in 1998 and in summer. Granada was the province with greatest risk (odds ratio = 2.6) of carriers (18.8% infected). The predisposing factors were sex (females), age (young animals), and metapopulation (Sierra Nevada). We identified a higher number of infected ibexes in the metapopulation "Sierra Nevada" (34/ 256) and significant differences among the three established metapopulations (P<0.01). Mycoplasma agalactiae infection represents a risk for population density and maintenance of these wild populations; infections can result in blindness, malnutrition, and polyarthritis leading to numerous deaths.

  6. Presence of Mycoplasma agalactiae in semen of naturally infected asymptomatic rams.

    PubMed

    Prats-van der Ham, Miranda; Tatay-Dualde, Juan; de la Fe, Christian; Paterna, Ana; Sánchez, Antonio; Corrales, Juan C; Contreras, Antonio; Gómez-Martín, Ángel

    2016-08-01

    The purpose of the present study was to assess the presence of Mycoplasma agalactiae (Ma), the main causative agent of ovine contagious agalactia (CA), in semen of naturally infected rams. Therefore, semen samples from 167 rams residing in three different artificial insemination (AI) centers of a CA-endemic area were studied by microbiological and molecular techniques. In addition, serial ejaculates from the same rams were evaluated to determine the excretion dynamics of Ma. Of the 384 samples studied, Ma was detected in 56 (14.58%) which belonged to 44 different rams (26.35%). These findings confirm the ability of Ma to be excreted in semen of asymptomatic rams. Furthermore, these results also evidence the presence of these asymptomatic carriers of Ma in ovine AI centers, representing a serious health risk regarding the spread and maintenance of CA, especially in endemic areas. Moreover, the excretion of Ma in semen also points to the risk of venereal transmission of this disease. The current results highlight the need to implement control measures to prevent the admission of infected rams in AI centers and the necessity to continuously monitor semen samples to effectively detect infected individuals. PMID:27045625

  7. Presence of contagious agalactia causing mycoplasmas in Spanish goat artificial insemination centres.

    PubMed

    Amores, J; Gómez-Martín, A; Corrales, J C; Sánchez, A; Contreras, A; De la Fe, C

    2011-04-15

    Male goats admitted to artificial insemination centres come from herds that have shown no clinical symptoms of contagious agalactia (CA) for the last 6 mo. However, prior reports suggest that this control measure may not be completely effective. This study was designed to detect the presence of CA-causing mycoplasmas in 9 Spanish centres, comprising 159 goats (147 males and 12 teaser does) of 8 different breeds. A microbiological study was conducted during 8 mo on 448 samples (318 ear swabs, 119 semen samples and 11 milk samples). In 86 samples (84 swabs, 1 semen sample and 1 milk sample), CA-causative mycoplasmas were detected by PCR or culture, and 52 animals (49 goat males and 3 teaser does) tested positive. Most of these positive animals were auricular carriers (n = 50), mainly of Mycoplasma mycoides subsp. capri (Mmc), although some M. agalactiae (Ma) and, interestingly, M. capricolum subsp. capricolum (Mcc) carriers were also identified. At least 1 animal infected by CA-causing mycoplasmas was detected in 8 of the 9 centres (88.8%) although in most (66.7%) no infected animals or only 1 or 2 positive animals were identified. Our results indicate the presence of CA carriers as asymptomatic animals in reproductive programmes. These findings have already prompted efficient measures to detect and avoid the entry of these carriers in Spanish centres. We recommend similar measures for all centres in areas where CA is endemic.

  8. 21 CFR 526.820 - Erythromycin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Indications for use. Treatment of mastitis due to Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis in lactating or dry cows. (3) Limitations. Milk taken...

  9. 21 CFR 526.820 - Erythromycin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Indications for use. Treatment of mastitis due to Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis in lactating or dry cows. (3) Limitations. Milk taken...

  10. Early detection of neonatal group B streptococcus sepsis and the possible diagnostic utility of IL-6, IL-8, and CD11b in a human umbilical cord blood in vitro model

    PubMed Central

    Nakstad, Britt; Sonerud, Tonje; Solevåg, Anne Lee

    2016-01-01

    Background Group B streptococcus (GBS) infection remains a major cause of neonatal morbidity and mortality, and GBS III is the predominant strain in early-onset GBS neonatal sepsis. To avoid both over- and undertreatment of infants with nonspecific signs of infection, early diagnostic tools are warranted. The aim of this study was to identify biomarkers with high sensitivity and specificity in an early stage of GBS infection. A secondary aim was to assess the utility of a human umbilical cord blood (HUCB) model system of early-onset neonatal sepsis. Methods Umbilical cord blood samples from 20 healthy term pregnancies were stimulated for 2 hours with a GBS III isolate from a patient and a commercially available GBS Ia strain. Nonstimulated samples served as controls. Leukocyte surface markers (CD11b, CD64, toll-like receptor [TLR] 2, TLR4, and TLR6) were analyzed by flow cytometry and soluble biomarkers by enzyme-linked immunosorbent assay (interleukin [IL]-6 and -8; interferon-γ-inducing protein [IP]-10; and S100b). The area under the receiver operating characteristic curve (AUC) was calculated for the markers. Results GBS III gave the highest responses and AUC values for all biomarkers. Only IL-6 and IL-8 displayed an AUC approaching 0.8 for both GBS serotypes (P<0.001). IL-8 >5,292 pg/mL had both a sensitivity and a specificity of 1.00. IL-6 >197 pg/mL had both a sensitivity and a specificity of 0.95 for GBS III stimulation. CD11b on granulocytes and monocytes was the leukocyte surface marker with the highest AUC values for both GBS serotypes. Conclusion In agreement with previous studies, IL-6, IL-8, and potentially CD11b could be useful in diagnosing neonatal GBS infection in an early stage. Our HUCB early-onset neonatal sepsis model may be useful for evaluating biomarkers of neonatal sepsis. The HUCB of neonates with risk factors for sepsis might even be used for diagnostic purposes, but requires further study. PMID:27468243

  11. Group A Streptococcus endometritis following medical abortion.

    PubMed

    Gendron, Nicolas; Joubrel, Caroline; Nedellec, Sophie; Campagna, Jennifer; Agostini, Aubert; Doucet-Populaire, Florence; Casetta, Anne; Raymond, Josette; Poyart, Claire; Kernéis, Solen

    2014-07-01

    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

  12. 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

  13. Salivaricin G32, a Homolog of the Prototype Streptococcus py