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occurrence of pasteurella multocida among pigs with respiratory disease in china between 2011 and 2015.prior to the 1990s, p. multocida capsular serogroup a was the most prevalent in china, followed by serogroups b and d. thirty years later, serogroup d became the most prevalent, followed by serogroups a and b. however, the p. multocida capsular serogroups currently circulating in china remain unclear. therefore, the aim of the present study was to provide an update on p. multocida serogroups isolated from diagnostic samples collected from clinically diseased pigs in central and eastern china fro ...201728078081
survey of susceptibility to marbofloxacin in bacteria isolated from diseased pigs in europe.a monitoring programme of marbofloxacin susceptibility of bacteria from europe causing respiratory tract infection and meningitis in pigs has been active since 1994 and 2002, respectively. monitoring digestive, metritis and urinary tract infection (uti) in pigs has been active since 2005 and susceptibility results until 2013 are presented. minimum inhibitory concentration (mic) was determined by broth microdilution. for mic interpretation, vétoquinol-evaluated breakpoints were applied. for diges ...201728348142
causes and outcomes of sepsis in southeast asia: a multinational multicentre cross-sectional study.improved understanding of pathogens that cause sepsis would aid management and antimicrobial selection. in this study, we aimed to identify the causative pathogens of sepsis in southeast asia.201728104185
streptococcus suis sortase a is ca2+ independent and is inhibited by acteoside, isoquercitrin and baicalin.sortase a (srta) has long been recognized as an ideal drug target for therapeutic agents against gram-positive pathogens. however, the srta of streptococcus suis (ss-srta), an important zoonotic agent, has not been studied. in this study, the enzymatic properties of ss-srta were investigated, and inhibition of ss-srta by natural products was evaluated. ss-srta was expressed and purified. the purified recombinant ss-srta had maximal activity at ph 6.0-7.5, 45°c, and showed a km of 6.7 μm for the ...201728319184
in vitro and in vivo antibacterial effect of nz2114 against streptococcus suis type 2 infection in mice peritonitis models.nz2114 is a promising candidate for therapeutic application owing to potent activity to gram-positive bacterium such as streptococcus pneumoniae and staphylococcus aureus. this work is the first report to describe the in vitro and in vivo antibacterial characteristics of nz2114 against streptococcus suis. it exhibited strong antimicrobial activity against s. suis type 2 strains cvcc 606, cvcc 3309, and cvcc 3928 at a low minimal inhibitory concentration (mic) of 0.03-0.06 μm. the nz2114 killed o ...201728220445
lysine-tryptophan-crosslinked peptides produced by radical sam enzymes in pathogenic streptococci.macrocycles represent a common structural framework in many naturally occurring peptides. several strategies exist for macrocyclization, and the enzymes that incorporate them are of great interest, as they enhance our repertoire for creating complex molecules. we recently discovered a new peptide cyclization reaction involving a crosslink between the side chains of lysine and tryptophan that is installed by a radical sam enzyme. herein, we characterize relatives of this metalloenzyme from the pa ...201728191919
survival of streptococcus suis, streptococcus dysgalactiae and trueperella pyogenes in dry-cured iberian pork shoulders and loins.dry-cured hams, shoulders and loins of iberian pigs are highly appreciated in national and international markets. salting, additive addition and dehydration are the main strategies to produce these ready-to-eat products. although the dry curing process is known to reduce the load of well-known food borne pathogens, studies evaluating the viability of other microorganisms in contaminated pork have not been performed. in this work, the efficacy of the dry curing process to eliminate three swine pa ...201727697171
a locus encoding variable defence systems against invading dna identified in streptococcus suis.streptococcus suis, an important zoonotic pathogen, is known to have an open pan-genome and to develop a competent state. in s. suis, limited genetic lineages are suggested to be associated with zoonosis. however, little is known about the evolution of diversified lineages and their respective phenotypic or ecological characteristics. in this study, we performed comparative genome analyses of s. suis, with a focus on the competence genes, mobile genetic elements (mges), and genetic elements rela ...201728379509
streptococcus suis serotype 2 biofilms inhibit the formation of neutrophil extracellular traps.invasive infections caused by streptococcus suis serotype 2 (ss2) has emerged as a clinical problem in recent years. neutrophil extracellular traps (nets) are an important mechanism for the trapping and killing of pathogens that are resistant to phagocytosis. biofilm formation can protect bacteria from being killed by phagocytes. until now, there have only been a few studies that focused on the interactions between bacterial biofilms and nets. ss2 in both a biofilm state and a planktonic cell st ...201728373968
morin attenuates streptococcus suis pathogenicity in mice by neutralizing suilysin activity.streptococcus suis, a gram-positive pathogen, is widely recognized as an important agent of swine infection, and it is also known to cause a variety of zoonoses, such as meningitis, polyarthritis and pneumonia. suilysin (sly), an extracellular pore-forming toxin that belongs to the cholesterol-dependent cytolysin family, is an essential virulence factor of s. suis capsular type 2 (ss2). here, we found that morin hydrate (morin), a natural flavonoid that lacks anti-ss2 activity, inhibits the hemo ...201728373868
the non-conserved region of mrp is involved in the virulence of streptococcus suis serotype 2.muramidase-released protein (mrp) of streptococcus suis serotype 2 (ss2) is an important epidemic virulence marker with an unclear role in bacterial infection. to investigate the biological functions of mrp, three mutants named δmrp, δmrp domain 1 (δmrp-d1), and δmrp domain 2 (δmrp-d2) were constructed to assess the phenotypic changes between the parental strain and the mutant strains. the results indicated that mrp domain 1 (mrp-d1, the non-conserved region of mrp from a virulent strain, a.a. 2 ...201728362221
porcine dendritic cells as an in vitro model to assess the immunological behaviour of streptococcus suis subunit vaccine formulations and the polarizing effect of adjuvants.an in vitro porcine bone marrow-derived dendritic cell (dc) culture was developed as a model for evaluating immune polarization induced by adjuvants when administered with immunogens that may become vaccine candidates if appropriately formulated. the swine pathogen streptococcus suis was chosen as a prototype to evaluate proposed s. suis vaccine candidates in combination with the adjuvants poly i:c, quil a ®, alhydrogel ®, titermax gold ® and stimune ®. the toll-like receptor ligand poly i:c and ...201728327531
the eukaryote-like serine/threonine kinase stk regulates the growth and metabolism of zoonotic streptococcus suis.like eukaryotes, bacteria express one or more serine/threonine kinases (stks) that initiate diverse signaling networks. the stk from streptococcus suis is encoded by a single-copy stk gene, which is crucial in stress response and virulence. to further understand the regulatory mechanism of stk in s. suis, a stk deletion strain (δstk) and its complementary strain (cδstk) were constructed to systematically decode stk characteristics by applying whole transcriptome rna sequencing (rna-seq) and phos ...201728326294
better understanding of homologous recombination through a 12-week laboratory course for undergraduates majoring in biotechnology.homologous recombination, a central concept in biology, is defined as the exchange of dna strands between two similar or identical nucleotide sequences. unfortunately, undergraduate students majoring in biotechnology often experience difficulties in understanding the molecular basis of homologous recombination. in this study, we developed and implemented a 12-week laboratory course for biotechnology undergraduates in which gene targeting in streptococcus suis was used to facilitate their underst ...201728314074
genome-wide analysis of a avirulent and reveal the strain induces pro-tective immunity against challenge with virulent streptococcus suis serotype 2.it was previously reported in china that two recent large-scale outbreaks of streptococcus suis serotype 2 (s. suis 2) infections in human were caused by two highly virulent s. suis 2 strains, from which a novel genomic island (gei), associated with disease onset and progression and designated 89 k, was identified. here, an avirulent strain, 05has68, was isolated from a clinically healthy pig.201728292261
critical streptococcus suis virulence factors: are they all really critical?streptococcus suis is an important swine pathogen that can be transmitted to humans by contact with diseased animals or contaminated raw pork products. this pathogen possesses a coat of capsular polysaccharide (cps) that confers protection against the immune system. yet, the cps is not the only virulence factor enabling this bacterium to successfully colonize, invade, and disseminate in its host leading to severe systemic diseases such as meningitis and toxic shock-like syndrome. indeed, recent ...201728274524
case report: two human streptococcus suis infections in borneo, sabah, malaysia.streptococcus suis (s.suis) is increasingly being recognised as a potentially preventable emerging zoonotic infection in humans with a global distribution. it is a major cause of meningitis especially among those in contact with pigs and has also been associated with a toxic shock syndrome.201728257622
capsular serotypes, virulence-associated genes and antimicrobial susceptibility of streptococcus suis isolates from pigs in korea.streptococcus suis is an important pig pathogen with potential for human transmission. the serotype distributions and phenotypic characteristics vary over time and among regions; however, little is known about the characteristics of s. suis isolates in korea. in this study, 240 s. suis isolates collected from pigs in korea in 2009-2010 were serotyped by coagglutination tests, subsequently screened for three virulence-associated genes (mrp, epf and sly) and tested for antimicrobial susceptibility ...201728250312
genotyping and investigating capsular polysaccharide synthesis gene loci of non-serotypeable streptococcus suis isolated from diseased pigs in canada.streptococcus suis (s. suis) is an important swine pathogen and an emerging zoonotic agent. most clinical s. suis strains express capsular polysaccharides (cps), which can be typed by antisera using the coagglutination test. in this study, 79 s. suis strains recovered from diseased pigs in canada and which could not be typed using antisera were further characterized by capsular gene typing and sequencing. four patterns of cps locus were observed: (1) fifteen strains were grouped into previously ...201728219415
transcriptomic analysis reveals selective metabolic adaptation of streptococcus suis to porcine blood and cerebrospinal fluid.streptococcus suis is a zoonotic pathogen that can cause severe pathologies such as septicemia and meningitis in its natural porcine host as well as in humans. establishment of disease requires not only virulence of the infecting strain but also an appropriate metabolic activity of the pathogen in its host environment. however, it is yet largely unknown how the streptococcal metabolism adapts to the different host niches encountered during infection. our previous isotopologue profiling studies o ...201728212285
syringa oblata lindl. aqueous extract is a potential biofilm inhibitor in s. suis.streptococcus suis (s. suis) is a zoonotic pathogen that causes severe disease symptoms in pigs and humans. syringa oblata lindl. distributed in the middle latitudes of eurasia and north america were proved as the most development potential of chinese medicine. in this study, biofilm formation by s. suis decreased after growth with 1/2 mic, 1/4 mic, or 1/8 mic of syringa oblata lindl. aqueous extract and rutin. scanning electron microscopy analysis revealed the potential effect of syringa oblata ...201728194111
isolation and partial characterization of streptococcus suis from clinical cases in cattle.sixteen isolates of gram-positive, coccoid bacteria were obtained from clinical cases of diverse conditions in cattle and identified as streptococcus suis using 16s ribosomal dna gene sequencing and other bacterial identification methods. none of the isolates could be assigned to any of the known s. suis capsular types. virulence-associated gene profiling that targeted muramidase-released protein, extracellular protein factor, suilysin, 89-kb pathogenicity island, and arginine deiminase ( arca) ...201728166707
factor h specifically capture novel factor h-binding proteins of streptococcus suis and contribute to the virulence of the bacteria.factor h (fh), a regulatory protein of the complement system, can bind specifically to factor h-binding proteins (fhbps) of streptococcus suis serotype 2 (ss2), which contribute to evasion of host innate immune defenses. in the present study, we aimed to identify novel fhbps and characterize the biological functions of fh in ss2 pathogenesis. here, a method that combined proteomics and far-western blotting was developed to identify the surface fhbps of ss2. with this method, fourteen potential n ...201728164787
transcutaneous immunization of streptococcus suis bacterin using dissolving microneedles.vaccine delivery using microneedle (mn) patches is an easy, safe and painless alternative to traditional needle injections. in this study, we examined whether mn patches can enhance the efficacy of a streptococcus suis serotype 2 (s. suis 2) vaccine in a mouse model. results showed that mns can reach 200-250μm into the skin, a depth beneficial for targeted delivery of antigens to antigen-presenting cells in the epidermis and dermis. vaccination with prime-boost of mn induced higher levels of igg ...201728131383
streptococcus suis small rna rss04 contributes to the induction of meningitis by regulating capsule synthesis and by inducing biofilm formation in a mouse infection model.streptococcus suis (ss) is an important pathogen for pigs, and it is also considered as a zoonotic agent for humans. meningitis is one of the most common features of the infection caused by ss, but little is known about the mechanisms of ss meningitis. recent studies have revealed that small rnas (srnas) have emerged as key regulators of the virulence in several bacteria. in the previous study, we reported that ss srna rss04 was up-regulated in pig cerebrospinal fluid and contributes to ss virul ...201728110777
draft genome sequence of hypervirulent and vaccine candidate streptococcus suis strain sc19.streptococcus suis, a zoonotic bacterium found primarily in pigs, has been recognized recently as an emerging pathogen of humans. herein, we describe the genome of streptococcus suis strain sc19, a hypervirulent and vaccine candidate strain isolated from a pig amid the 2005 outbreak in china.201728104658
the involvement of msmk in pathogenesis of the streptococcus suis serotype 2.streptococcus suis serotype 2 (ss2) is an important swine and human pathogen that causes global economic and public health problems. virulent s. suis strains successfully maintain high bacterial concentrations in host blood and rapidly adapt to challenging environments within hosts. successful survival in hosts is a major factor influencing the pathogenesis of ss2. we have previously identified that ss2 colonization in mouse brain is possibly affected by the atpase, msmk of carbohydrate atp-bind ...201728102028
serotypes of streptococcus suis isolated from healthy pigs in phayao province, thailand.streptococcus suis (s. suis) is an important swine and human pathogen. there are 33 serotypes that have been described. zoonotic cases are very common the northern part of thailand, especially in phayao province. however, the prevalence of s. suis and, more particularly the different serotypes, in pigs in this region is poorly known and needed to be addressed.201728100261
the 1910hk/rr two-component system is essential for the virulence of streptococcus suis serotype 2.streptococcus suis serotype 2 is a major zoonotic pathogen, and the two-component system plays an important role in bacterial pathogenesis. the present study targeted the 1910hk/rr two-component system of s. suis 2. a 1910hk/rr deletion mutant (δ1910hk/rr) and the corresponding complementation strain (cδ1910hk/rr) were constructed in s. suis 2 strain 05zyh33. 1910hk/rr deletion had no effect on s. suis 2 growth, but significantly inhibited the adherence and invasion of s. suis 2 to hep-2 cells. ...201728093234
pathogenic streptococcus strains employ novel escape strategy to inhibit bacteriostatic effect mediated by mammalian peptidoglycan recognition protein.pathogenic streptococcal species are responsible for some of the most lethal and prevalent animal and human infections. previous reports have identified a candidate pathogenicity island (pai) in two highly virulent clinical isolates of streptococcus suis type 2, a causative agent of high-mortality streptococcal toxic shock syndrome. this pai contains a type-ivc secretion system c subgroup (type-ivc secretion system) that is involved in the secretion of unknown pathogenic effectors that are respo ...201728092693
deletion of ssna attenuates the pathogenicity of streptococcus suis and confers protection against serovar 2 strain challenge.streptococcus suis serotype 2 (ss2) is a major porcine and human pathogen which causes arthritis, meningitis, and septicemia. streptococcus suis nuclease a (ssna) is a recently discovered deoxyribonuclease (dnase), which has been demonstrated to contribute to escape killing in neutrophil extracellular traps (nets). to further determine the effects of ssna on virulence, the ssna deletion mutant (δssna) and its complemented strain (c-δssna) were constructed. the ability of δssna mutant to interact ...201728081204
mac protein is not an essential virulence factor for the virulent reference strain streptococcus suis p1/7.streptococcus suis is a major pathogen of pigs and also an important zoonotic agent for humans. a s. suis protein containing mac-1 domain (designated mac) is a protective antigen, exclusively cleaves porcine igm, and contributes to complement evasion with the presence of high titers of specific porcine anti-s. suis igm, but its role in s. suis virulence has not been investigated in natural healthy host without specific igm. in this study, a mac deletion mutant was constructed by homologous recom ...201727847975
immunization with streptococcus suis bacterin plus recombinant sao protein in sows conveys passive immunity to their piglets.streptococcus suis (s. suis) causes arthritis, meningitis, septicemia, and sudden death in pigs and is also an zoonotic agent for humans. the present study demonstrated that immunization with recombinant sao-l (surface antigen one-l, rsao-l) protein from a strain of s. suis serotype 2 in pigs was able to increase cross-serotype protection against s. suis serotype 1 and 2 challenge. since weaning piglets are more susceptible to s. suis infections due to the stresses associated with weaning, prepa ...201728061775
development of an indirect dot-ppa-elisa using glutamate dehydrogenase as a diagnostic antigen for the rapid and specific detection of streptococcus suis and its application to clinical specimens.streptococcus suis is an important zoonotic pathogen causing infections in pigs and humans. bacterial surface-related proteins are often explored as potential vaccine candidates and diagnostic antigens. in the present study, glutamate dehydrogenase, a highly conserved immunogenic extracellular protein, was used to establish a dot horseradish peroxidase enzyme-linked staphylococcal protein a immunosorbent assay (dot-ppa-elisa) for diagnosis of s. suis infection. the antigen-antibody reaction was ...201728058577
a serine/threonine phosphatase 1 of streptococcus suis type 2 is an important virulence factor.streptococcus suis is regarded as one of the major pathogens of pigs while s. suis type 2 (ss2) is considered to be a zoonotic bacterium for its ability to cause meningitis and streptococcal toxic shock-like syndrome in humans. many bacterial species contain genes encoding serine/threonine protein phosphatases (stp) responsible for dephosphorylation of their substrates in a single reaction step. this study was aimed to investigate the role of stp1 in pathogenesis of ss2. an isogenic stp1 mutant ...201728057904
the phage lysin plyss2 decolonizes streptococcus suis from murine intranasal mucosa.streptococcus suis infects pigs worldwide and may be zoonotically transmitted to humans with a mortality rate of up to 20%. s. suis has been shown to develop in vitro resistance to the two leading drugs of choice, penicillin and gentamicin. because of this, we have pursued an alternative therapy to treat these pathogens using bacteriophage lysins. the bacteriophage lysin plyss2 is derived from an s. suis phage and displays potent lytic activity against most strains of that species including sero ...201728046082
detection of multiple parallel transmission outbreak of streptococcus suis human infection by use of genome epidemiology, china, 2005.streptococcus suis sequence type 7 emerged and caused 2 of the largest human infection outbreaks in china in 1998 and 2005. to determine the major risk factors and source of the infections, we analyzed whole genomes of 95 outbreak-associated isolates, identified 160 single nucleotide polymorphisms, and classified them into 6 clades. molecular clock analysis revealed that clade 1 (responsible for the 1998 outbreak) emerged in october 1997. clades 2-6 (responsible for the 2005 outbreak) emerged se ...201727997331
identification of a unique amyloid sequence in aa amyloidosis of a pig associated with streptococcus suis infection.here we report a pig with amyloid a (aa) amyloidosis associated with streptococcus suis infection and identification of a unique amyloid sequence in the amyloid deposits in the tissue. tissues from the 180-day-old underdeveloped pig contained foci of necrosis and suppurative inflammation associated with s. suis infection. congo red stain, immunohistochemistry, and electron microscopy revealed intense aa deposition in the spleen and renal glomeruli. mass spectrometric analysis of amyloid material ...201727520112
neutrophil extracellular trap formation in the streptococcus suis-infected cerebrospinal fluid compartment.streptococcus suis is an important meningitis-causing pathogen in pigs and humans. neutrophil extracellular traps (nets) have been identified as host defense mechanism against different pathogens. here, nets were detected in the cerebrospinal fluid (csf) of s. suis-infected piglets despite the presence of active nucleases. to study net-formation and net-degradation after transmigration of s. suis and neutrophils through the choroid plexus epithelial cell barrier, a previously described model of ...201727450700
contribution of nadh oxidase to oxidative stress tolerance and virulence of streptococcus suis serotype 2.streptococcus suis is a major swine and zoonotic pathogen that causes severe infections. previously, we identified 2 spx regulators in s. suis, and demonstrated that spxa1 affects oxidative stress tolerance and virulence. however, the mechanism behind spxa1 function remains unclear. in this study, we targeted 4 genes that were expressed at significantly reduced levels in the spxa1 mutant, to determine their specific roles in adaptation to oxidative stress and virulence potential. the δnox strain ...201727315343
nadh oxidase, a new player in the field of streptococcus suis infection. 201727482985
chronic osteomyelitis due to streptococcus suis: first case report from india. 201726069434
seven new lignan glycosides from the branches of alangium kurzii craib var. laxifolium.seven new lignan glycosides (1-3, 8-10, and 14) and 17 known compounds were isolated from the branches of alangium kurzii craib var. laxifolium. their structures were established by spectroscopic analysis and circular dichroism (cd) and x-ray analysis. the isolated compounds were evaluated for their antibacterial activities against staphylococcus aureus ci1011, streptococcus suis ci1608, salmonella gallinarum ci0912, enterococcus faecalis ci1304, aeromonas hydrophila ci1008, escherichia coli ci1 ...201728733150
comparison of asian porcine high fever disease isolates of porcine reproductive and respiratory syndrome virus to united states isolates for their ability to cause disease and secondary bacterial infection in swine.epidemiologic data from asian outbreaks of highly-pathogenic (hp) porcine reproductive and respiratory syndrome virus (prrsv) suggest that disease severity was associated with both the virulence of the prrsv isolates and secondary bacterial infections. previous reports have indicated that u.s. isolates of prrsv predispose to secondary bacterial infections as well, but the severity of disease that occurred in asia in pigs infected with these hp-prrsv strains has not been reported in the u.s. the ...201728619168
pathogen-reactive t helper cell analysis in the pig.there is growing interest in studying host-pathogen interactions in human-relevant large animal models such as the pig. despite the progress in developing immunological reagents for porcine t cell research, there is an urgent need to directly assess pathogen-specific t cells-an extremely rare population of cells, but of upmost importance in orchestrating the host immune response to a given pathogen. here, we established that the activation marker cd154 (cd40l), known from human and mouse studies ...201728567041
bacterial bloodstream infections in a tertiary infectious diseases hospital in northern vietnam: aetiology, drug resistance, and treatment outcome.bloodstream infections (bsis) are associated with high morbidity and mortality worldwide. however their aetiology, antimicrobial susceptibilities and associated outcomes differ between developed and developing countries. systematic data from vietnam are scarce. here we present aetiologic data on bsi in adults admitted to a large tertiary referral hospital for infectious diseases in hanoi, vietnam.201728701159
activation of invariant natural killer t cells stimulated with microbial α-mannosyl glycolipids.some synthetic and bacterial glycolipids presented by cd1d specifically activate invariant nkt (inkt) cells bearing an invariant vα14-jα18 (mouse) or vα24-jα18 (human) tcr. the antigenic glycolipids identified to date consist of two hydrophobic chains and an α-glycoside in which the 2'-oh group is in the cis orientation toward the anomeric group, namely, either an α-galactoside or an α-glucoside. several microbial α-mannosyl glycolipids, in which the 2'-oh group is in the trans orientation, were ...201728852174
microbiological zoonotic emerging risks, transmitted between livestock animals and humans (2007-2015).as part of the emerging risk identification (eri) activities of the european food safety authority (efsa), a literature search was conducted to identify the microbiological agents transmitted between livestock animals and humans that have been suggested as having emerged between 2007 and 2015 in peer-reviewed scientific literature published during the same period (2007-2015). according to the criteria set, the search identified seven such zoonotic agents, namely west nile fever virus, rift valle ...201728670863
preferential aerosolization of bacteria in bioaerosols generated in vitro.little is known about how bacteria are aerosolized in terms of whether some bacteria will be found in the air more readily than others that are present in the source. this report describes in vitro experiments to compare aerosolization rates (also known as preferential aerosolization) of gram-positive and gram-negative bacteria as well as rod- and coccus-shaped bacteria, using two nebulization conditions.201728632907
defining the taxonomic status of streptococcus suis serotype 33: the proposal for streptococcus ruminantium sp. nov.to clarify the taxonomic classification of streptococcus suis serotype 33, we performed biochemical and molecular genetic analyses using isolates (gut-183, gut-184, gut-185, gut-186, gut-187t, gut-188, gut-189, gut-190, gut-191, gut-192 and gut-193) from bovine endocarditis. a comparative sequence analysis showed 99.2-100 % sequence similarity among the reference strain of s. suis serotype 33 and our isolates for the 16s rrna gene. these similarities were higher than those between the isolate gu ...201728840807
streptococcus suis serotype 9 strain gz0565 contains a type vii secretion system putative substrate esxa that contributes to bacterial virulence and a vanz-like gene that confers resistance to teicoplanin and dalbavancin in streptococcus agalactiae.streptococcus suis (ss), an important pathogen for pigs, is not only considered as a zoonotic agent for humans, but is also recognized as a major reservoir of antimicrobial resistance contributing to the spread of resistance genes to other pathogenic streptococcus species. in addition to serotype 2 (ss2), serotype 9 (ss9) is another prevalent serotype isolated from diseased pigs. although many ss strains have been sequenced, the complete genome of a non-ss2 virulent strain has been unavailable t ...201728622857
a positive feedback loop mediated by sigma x enhances expression of the streptococcal regulator comr.natural transformation is used by bacteria to take up dna from their surroundings and incorporate it into their genomes. streptococci do so during a transient period of competence, triggered by pheromones that they produce, secrete and sense under conditions influenced by the environment. in streptococcus mutans, streptococcus suis, and species of the bovis, salivarius and pyogenic groups of streptococci, the pheromone xip is sensed by the intra-cellular regulator comr, that in turn activates th ...201728729683
hsds, belonging to the type i restriction-modification system, contributes to the streptococcus suis serotype 2 survival ability in phagocytes.streptococcus suis serotype 2 (ss2) is an important zoonotic agent in swine and humans. anti-phagocytosis and survival in phagocytic cells and whole blood is essential for bacteria to be pathogenic. in this study, the host specificity determinant specificity subunit (coded by hsds) of the type i restriction-modification system and two peptidoglycan-binding proteins (coded by lysm and lysm', respectively), which were simultaneously found to be subjected to transcript-level influence by hsds, were ...201728848531
hp1330 contributes to streptococcus suis virulence by inducing toll-like receptor 2- and erk1/2-dependent pro-inflammatory responses and influencing in vivo s. suis loads.streptococcus suis 2 (ss2) has evolved into a highly invasive pathogen responsible for two large-scale outbreaks of streptococcal toxic shock-like syndrome (stsls) in china. excessive inflammation stimulated by ss2 is considered a hallmark of stsls, even it also plays important roles in other clinical symptoms of ss2-related disease, including meningitis, septicemia, and sudden death. however, the mechanism of ss2-caused excessive inflammation remains poorly understood. here, a novel pro-inflamm ...201728824616
characterization of a novel streptococcal heme-binding protein snta and its interaction with host antioxidant protein aop2.efficient iron acquisition is critical for bacteria's survival, virulence and pathology of diseases. the largest reservoir of iron in mammals is incorporated into heme, which can be acquired by bacterial pathogens as a nutritional iron source. in this study, a cell wall protein snta of streptococcus suis serotype 2 (ss2) was characterized as a novel heme-binding protein by using the pyridine hemochrome assay and icp-ms measurement. yeast two-hybrid and pull-down assays revealed that the snta pro ...201728823793
patterns of antimicrobial resistance in streptococcus suis isolates from pigs with or without streptococcal disease in england between 2009 and 2014.antimicrobial resistance in streptococcus suis, a global zoonotic pathogen of pigs, has been mostly studied only in diseased animals using surveys that have not evaluated changes over time. we compared patterns of resistance between s. suis isolates from clinical cases of disease (cc) and non-clinical case (ncc) pigs in england, collected over two discrete periods, 2009-2011 and 2013-2014. minimum inhibitory concentrations (mic) of 17 antimicrobials (nine classes) were determined on 405 s. suis ...201728757010
the bias of experimental design, including strain background, in the determination of critical streptococcus suis serotype 2 virulence factors.streptococcus suis serotype 2 is an important porcine bacterial pathogen and emerging zoonotic agent mainly responsible for sudden death, septic shock, and meningitis. however, serotype 2 strains are genotypically and phenotypically heterogeneous. though a multitude of virulence factors have been described for s. suis serotype 2, the lack of a clear definition regarding which ones are truly "critical" has created inconsistencies that have only recently been highlighted. herein, the involvement o ...201728753679
sub-minimum inhibitory concentrations of rhubarb water extracts inhibit streptococcus suis biofilm formation.streptococcus suis is one of the most important swine pathogens, which can cause persistent infection by forming biofilms. in this study, sub-minimum inhibitory concentration (sub-mic) of rhubarb water extracts were found to inhibit biofilm formation. two-component signal transduction systems (tcss), transcriptional regulators, and dna binding proteins were compared under two conditions: (1) cells treated with sub-mic rhubarb water extracts and (2) untreated cells. using an isobaric tags for rel ...201728736523
impact of a food safety campaign on streptococcus suis infection in humans in thailand.abstractstreptococcus suis is an important zoonotic pathogen in swine and humans that causes sepsis and meningitis. our previous study in thailand showed that the prevalence of s. suis infection in humans, especially in northern areas of thailand, and the transmission of the pathogen occurred mainly through the consumption of traditional raw pork products. considering the high incidence proportion and mortality rate of the disease as an important public health problem, we implemented a food safe ...201728719258
natural killer cell functions during the innate immune response to pathogenic streptococci.dendritic cells (dcs) and nk cells play a crucial role in the first phase of host defense against infections. group b streptococcus (gbs) and streptococcus suis are encapsulated streptococci causing severe systemic inflammation, leading to septicemia and meningitis. yet, the involvement of nk cells in the innate immune response to encapsulated bacterial infection is poorly characterized. here, it was observed that these two streptococcal species rapidly induce the release of ifn-γ and that nk ce ...201728706510
serotype-specific role of antigen i/ii in the initial steps of the pathogenesis of the infection caused by streptococcus suis.streptococcus suis is one of the most important post-weaning porcine bacterial pathogens worldwide. the serotypes 2 and 9 are often considered the most virulent and prevalent serotypes involved in swine infections, especially in europe. however, knowledge of the bacterial factors involved in the first steps of the pathogenesis of the infection remains scarce. in several pathogenic streptococci, expression of multimodal adhesion proteins known as antigen i/ii (agi/ii) have been linked with persis ...201728705175
erratum to: genome-wide analysis of an avirulent strain that induces protective immunity against challenge with virulent streptococcus suis serotype 2. 201728676041
rutin inhibits streptococcus suis biofilm formation by affecting cps biosynthesis.streptococcus suis (s. suis) form biofilms and causes severe diseases in humans and pigs. biofilms are communities of microbes embedded in a matrix of extracellular polymeric substances. eradicating biofilms with the use of antibiotics or biocides is often ineffective and needs replacement with other potential agents. compared to conventional agents, promising and potential alternatives are biofilm-inhibiting compounds without impairing growth. here, we screened a s. suis adhesion inhibitor, rut ...201728670278
a single amino acid polymorphism in the glycosyltransferase cpsk defines four streptococcus suis serotypes.the capsular polysaccharide (cps) is the major virulence factor of the emerging zoonotic pathogen streptococcus suis. cps differences are also the basis for serological differentiation of the species into 29 serotypes. serotypes 2 and 1/2, which possess identical gene content in their cps loci, express cpss that differ only by substitution of galactose (gal) by n-acetylgalactosamine (galnac) in the cps side chain. the same sugar substitution differentiates the cps of serotypes 14 and 1, whose cp ...201728642597
the manganese efflux system mnte contributes to the virulence of streptococcus suis serotype 2.manganese is an essential micronutrient to bacteria and plays an important role in bacterial physiology. however, an excess of manganese is extremely deleterious to the cell. the manganese efflux system is used to control intracellular manganese levels by some bacteria. in this study, we have identified a cation efflux family protein (mnte) that functions as a manganese export system in streptococcus suis serotype 2. to investigate the role of mnte in s. suis 2, a mnte deletion mutant (δmnte) an ...201728629722
the streptococcus suis factor h-binding protein: a key to unlocking the blood-brain barrier and access the central nervous system? 201728622084
prevalence of multiple drug resistant streptococcus suis in and around guwahati, india.this study was conducted to determine the prevalence and antimicrobial susceptibility of streptococcus suis and their resistance patterns isolated from both clinically healthy carriers and diseased pigs in and around guwahati, assam, india.201728620262
differences in microbiota membership along the gastrointestinal tract of piglets and their differential alterations following an early-life antibiotic intervention.early-life antibiotic interventions can change the predisposition to disease by disturbing the gut microbiota. however, the impact of antibiotics on gut microbiota in the gastrointestinal tract is not completely understood, although antibiotic-induced alterations in the distal gut have been reported. here, employing a piglet model, the microbial composition was analyzed by high-throughput 16s rrna gene sequencing and picrust predictions of metagenome function. the present study showed clear spat ...201728536561
potentially hazardous streptococcus suis strains latent in asymptomatic pigs in a major swine production area of thailand.carrier pigs have been considered as the major reservoir of streptococcus suis and couldbe a significant source of human infection. therefore, we investigated the prevalence and characteristics of latent s. suis in asymptomatic pigs in the pig-farming area of central thailand, and compared the data to those previously reported in other regions.201728516843
draft genome sequence of clinical strain tani1 of streptococcus suis serotype 5 isolated from a bacteremia patient in japan.streptococcus suis is a swine pathogen that causes severe economic damage to the porcine industry. it occasionally evokes zoonotic infection in humans. here, we report a draft genome sequence of a s. suis serotype 5 strain isolated from a bacteremia patient that was reported by taniyama et al. (d. taniyama, m. sakurai, t. sakai, t. kikuchi, and t. takahashi, idcases 6:36-38, 2016, https://doi.org/10.1016/j.idcr.2016.09.011).201728473377
muramidase-released protein of streptococcus suis: new insight into its impact on virulence. 201728467144
expression and characterization of serotype 2 streptococcus suis arginine deiminase.arginine deiminase (arca) has been speculated to facilitate the intracellular survival of streptococcus suis under acidic conditions. however, the physical and biological properties and function of ss2-arca have not yet been elucidated.201728456803
evaluation of the immunomodulatory properties of streptococcus suis and group b streptococcus capsular polysaccharides on the humoral response.streptococcus suis and group b streptococcus (gbs) are encapsulated streptococci causing septicemia and meningitis. antibodies (abs) against capsular polysaccharides (cpss) have a crucial protective role, but the structure/composition of the cps, including the presence of sialic acid, may interfere with the generation of anti-cps ab responses. we investigated the features of the cps-specific ab response directed against s. suis serotypes 2 and 14 and gbs serotypes iii and v after infection or im ...201728425925
streptococcal adhesin p (sadp) contributes to streptococcus suis adhesion to the human intestinal epithelium.streptococcus suis is a zoonotic pathogen, causing meningitis and septicemia. we previously demonstrated that the gastrointestinal tract (git) is an entry site for zoonotic s. suis infection. here we studied the contribution of streptococcal adhesin protein (sadp) to host-pathogen interaction at git level.201728407026
interaction of factor h-binding protein of streptococcus suis with globotriaosylceramide promotes the development of meningitis.streptococcus suis is an important emerging zoonotic agent that causes acute bacterial meningitis in humans with high mortality and morbidity. our previous work showed that factor h-binding protein (fhb) contributed to virulence of s. suis, but the role of fhb in the development of s. suis meningitis remained unclear. in this study, we demonstrated for the first time that fhb contributed to the traversal of s. suis across the human blood-brain barrier by allelic-exchange mutagenesis, complementa ...201728402705
a novel prophage lysin ply5218 with extended lytic activity and stability against streptococcus suis infection.streptococcus suis (s. suis) is an emerging zoonotic agent that exhibits high level resistance to classic antibiotics and a heavy burden in the swine industry. therefore alternative antibacterial agents need to be developed. a novel endolysin derived from the s. suis temperate phage phi5218, termed ply5218, was identified. the minimum inhibitory concentration (mic) of ply5218 was 2.5 μg ml(-1) against s. suis strain ha9801, an activity many times greater than the lysins reported previously (mic ...201627481700
characterization of the immune response and evaluation of the protective capacity of rssna against streptococcus suis infection in pigs.the efforts made to develop vaccines against streptococcus suis have failed because of lack of common antigens cross-reactive against different serotypes of this species. the cell wall-anchored proteins can be good vaccine candidates due to their high expression and accessibility to antibodies, among these, a cell-wall protein, dna-nuclease (ssna), present in most of the s. suis serotypes and clinical isolates collected from infected pigs, was selected. an experimental challenge against s. suis ...201627477507
characterization of spectinomycin resistance in streptococcus suis leads to two novel insights into drug resistance formation and dissemination mechanism.spectinomycin is an aminocyclitol antibiotic used clinically to treat a variety of infections in animals. here, we characterized drug resistance prevalence in clinical streptococcus suis isolates and discovered a novel resistance mechanism in which the s5 mutation (gly26asp) results in high spectinomycin resistance. additionally, a novel integrative and conjugative element encompassing a multidrug resistance spw_like-aade-lnu(b)-lsa(e) cluster and a cadmium resistance operon were identified, sug ...201627458226
flps, the fnr-like protein of streptococcus suis is an essential, oxygen-sensing activator of the arginine deiminase system.streptococcus (s.) suis is a zoonotic pathogen causing septicemia and meningitis in pigs and humans. during infection s. suis must metabolically adapt to extremely diverse environments of the host. ccpa and the fnr family of bacterial transcriptional regulators are important for metabolic gene regulation in various bacteria. the role of ccpa in s. suis is well defined, but the function of the fnr-like protein of s. suis, flps, is yet unknown. transcriptome analyses of wild-type s. suis and a flp ...201627455333
a novel virulence-associated protein, vape, in streptococcus suis serotype 2.streptococcus suis serotype 2 (ss2) is an important pathogen that affects pigs. however, neither its virulence nor its pathogenesis of infection has yet to be fully elucidated. the present study identifies a novel virulence‑associated protein e gene (vape) of ss2. to investigate the importance of vape in ss2 infection, a vape knock‑out mutant based on ss2 wild‑type strain zy458 was designated 458δvape. 458δvape was generated through homologous recombination, using a combined plasmid with a vape ...201626821177
characterization of iga1 protease as a surface protective antigen of streptococcus suis serotype 2.iga1 protease of streptococcus suis serotype 2 (ss2) has been proven to be relative with virulence and immunogenicity, however, its protective efficacy remained to be evaluated. the present study found evidence that immunization with purified recombinant iga1 protease (600-1926aa) could induce high igg antibody titers and could confer complete protection against a challenge with a lethal dose of ss2 in a mouse model. in addition, our findings confirmed that the iga1 protease distributes on the s ...201626774332
enolase of streptococcus suis serotype 2 enhances blood-brain barrier permeability by inducing il-8 release.streptococcus suis serotype 2 (ss2) is an emerging zoonosis, and meningitis is the most frequent clinical manifestation, but mechanism of its virulent factor, enolase (eno), is unknown in meningitis. in this study, eno was inducibly expressed and added to an in vitro transwell co-culture model of the blood-brain barrier (bbb) consisted of porcine brain microvascular endothelial cells (pbmecs) and astrocytes (acs), the results showed that eno induces a significant increase in bbb permeability and ...201626732390
temporal and spatial association of streptococcus suis infection in humans and porcine reproductive and respiratory syndrome outbreaks in pigs in northern vietnam.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 ...201625997360
in vivo pharmacodynamics of cefquinome in a neutropenic mouse thigh model of streptococcus suis serotype 2 at varied initial inoculum sizes.streptococcus suis serotype 2 is an emerging zoonotic pathogen and causes severe disease in both pigs and human beings. cefquinome (ceq), a fourth-generation cephalosporin, exhibits broad-spectrum activity against gram-positive bacteria such as s. suis. this study evaluated the in vitro and in vivo antimicrobial activities of ceq against four strains of s. suis serotype 2 in a murine neutropenic thigh infection model. we investigated the effect of varied inoculum sizes (10(6) to 10(8) cfu/thigh) ...201626666923
a cluster of streptococcus suis meningitis in a family who traveled to taiwan from southern vietnam. 201625081989
astrocytes enhance streptococcus suis-glial cell interaction in primary astrocyte-microglial cell co-cultures.streptococcus (s.) suis infections are the most common cause of meningitis in pigs. moreover, s. suis is a zoonotic pathogen, which can lead to meningitis in humans, mainly in adults. we assume that glial cells may play a crucial role in host-pathogen interactions during s. suis infection of the central nervous system. glial cells are considered to possess important functions during inflammation and injury of the brain in bacterial meningitis. in the present study, we established primary astrocy ...201627304968
antimicrobial activity of penicillin g and n-acetylcystein on planktonic and sessile cells of streptococcus suis.the aim of this study was to investigate the capacity of streptococcus suis strains to form biofilms and to evaluate the antimicrobial activity of penicillin g and n-acetylcystein (nac) on both s. suis sessile and planktonic forms. only non-typeable isolates of s. suis were correlated with a greater biofilm formation capacity. the mci of penicillin g and nac required for inhibiting biofilm growth were higher than the required concentration for inhibiting planktonic growth. the combinations of na ...201627282001
subtilisin-like protease-1 secreted through type iv secretion system contributes to high virulence of streptococcus suis 2.streptococcus suis serotype 2 is an emerging zoonotic pathogen that triggered two outbreaks of streptococcal toxic shock syndrome (stss) in china. our previous research demonstrated that a type iv secretion system (t4ss) harbored in the 89k pathogenicity island contributes to the pathogenicity of s. suis 2. in the present study, a shotgun proteomics approach was employed to identify the effectors secreted by t4ss in s. suis 2, and surface-associated subtilisin-like protease-1 (sspa-1) was identi ...201627270879
the roles of rela/(p)ppgpp in glucose-starvation induced adaptive response in the zoonotic streptococcus suis.the (p)ppgpp signal molecules play a central role in the stringent response (sr) to adapt to nutrient starvation in bacteria, yet the carbohydrate starvation induced adaptive response and the roles of sr in this response is not well characterized, especially in gram-positives. here, two (p)ppgpp synthetases rela and relq are identified in streptococcus suis, an important emerging zoonotic gram-positive bacterium, while only rela is functional under glucose starvation. to characterize the roles o ...201627255540
efficient suilysin-mediated invasion and apoptosis in porcine respiratory epithelial cells after streptococcal infection under air-liquid interface conditions.streptococci may colonize the epithelium in the airways and other entry sites. while local infection often remains asymptomatic, severe or even fatal diseases occur when streptococci become invasive and spread to different sites in the infected host. we have established porcine respiratory air-liquid interface cultures (ali) from the porcine lung to analyze the interaction of streptococci with their primary target cells. as representative of the streptococcal family we chose streptococcus suis ( ...201627229328
loss of 89k pathogenicity island in epidemic streptococcus suis, china. 201627192444
impact of serotype and sequence type on the preferential aerosolization of streptococcus suis.streptococcus suis is a swine pathogen that causes pneumonia, septicemia and meningitis. it is also an important zoonotic agent responsible of several outbreaks in china. s. suis strains are classified into 35 serotypes based on the composition of their polysaccharide capsule. s. suis serotype 2 causes the majority of severe infections in pigs and in human, and can be further subdivided into sequence types (sts) based on multilocus sequence typing. the st1 is associated with highly virulent stra ...201627180230
metabolic context of the competence-induced checkpoint for cell replication in streptococcus suis.natural genetic transformation is a transient, rapidly progressing energy-consuming process characterized by expression of the transformasome and competence-associated regulatory genes. this transient state is tightly controlled to avoid potentially adverse effects of genetic recombination on genome integrity during cell division. we investigated the global response of streptococcus suis to exposure to the sigx competence-inducing peptide (xip), and thus to the activation of the competence machi ...201627149631
monitoring of antimicrobial susceptibility of streptococcus suis in the netherlands, 2013-2015.the objective of the present study was to analyse the in vitro antimicrobial susceptibility of streptococcus suis isolates from post-mortem samples from pigs in the netherlands. s. suis isolates originated from diagnostic submissions of pigs sent to the pathology department of gd animal health, from april 2013 till june 2015. minimal inhibitory concentrations (mics) of in total 15 antimicrobials were assessed by broth microdilution following clsi recommendations. mic50 and mic90 values were dete ...201627131836
genetic diversity of streptococcus suis serotype 2 isolated from pigs in brazil.streptococcus suis is an emerging zoonotic pathogen that causes septicemia, meningitis, arthritis, and pneumonia in swine and humans. the present study aimed to characterize the genetic diversity of s. suis serotype 2 isolated from pigs showing signs of illness in brazil using pulsed-field gel electrophoresis (pfge), single-enzyme amplified fragment length polymorphism (se-aflp), and profiling of virulence-associated markers. a total of 110 isolates were studied, 62.7% of which were isolated fro ...201627127337
impact of sub-inhibitory concentrations of amoxicillin on streptococcus suis capsule gene expression and inflammatory potential.streptococcus suis is an important swine pathogen and emerging zoonotic agent worldwide causing meningitis, endocarditis, arthritis and septicemia. among the 29 serotypes identified to date, serotype 2 is mostly isolated from diseased pigs. although several virulence mechanisms have been characterized in s. suis, the pathogenesis of s. suis infections remains only partially understood. this study focuses on the response of s. suis p1/7 to sub-inhibitory concentrations of amoxicillin. first, caps ...201627104570
structural basis of the interaction between the meningitis pathogen streptococcus suis adhesin fhb and its human receptor.the recently identified streptococcus suis adhesin factor h-binding protein (fhb) targets the host cellular receptor glycolipid gbo3 through its n terminus. however, it is unclear how fhb interacts with its receptor. here, we determined the complex structure of factor h-binding protein receptor-binding domain (fhb rbd) with gb2, an analog of its receptor, revealing that gb2 binds in a pocket of the β sandwich core domain. we identified the key residues for fhb rbd receptor binding using mutagene ...201627086582
sbp2 plays an important role in the virulence changes of different artificial mutants of streptococcus suis.streptococcus suis (ss) is an important bacterial zoonotic pathogen, which can cause infections in pigs and humans. however, the pathogenesis of this bacterium remains unclear, even though some putative virulence factors (vfs) have been reported. comparative proteomics could be used to identify markers that can distinguish bacterial strains with different virulence; however, the application of this method is restricted by the genome diversities existing in different strains. in this study, two m ...201627077729
a streptococcus suis lysm domain surface protein contributes to bacterial virulence.streptococcus suis (ss) is a major swine pathogen, as well as a zoonotic agent for humans. numerous factors contribute to ss virulence, but the pathogenesis of ss infection is poorly understood. here, we show that a novel ss surface protein containing a lysm at the n-terminus (ss9-lysm) contributes to ss virulence. homology analysis revealed that the amino acid sequence of ss9-lysm from the ss strain gz0565 shares 99.8-68.7% identity with homologous proteins from other ss strains and 41.2% ident ...201627066710
sub-mic tylosin inhibits streptococcus suis biofilm formation and results in differential protein expression.streptococcus suis (s.suis) is an important zoonotic pathogen that causes severe diseases in humans and pigs. biofilms of s. suis can induce persistent infections that are difficult to treat. in this study, the effect of tylosin on biofilm formation of s. suis was investigated. 1/2 minimal inhibitory concentration (mic) and 1/4 mic of tylosin were shown to inhibit s. suis biofilm formation in vitro. by using the itraq strategy, we compared the protein expression profiles of s. suis grown with su ...201627065957
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