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Medecine Et Maladies Infectieuses May 2018Streptococcus suis is a major swine pathogen worldwide and causes considerable economic losses in the swine industry. S. suis is also an emerging zoonotic agent, mainly... (Review)
Review
Streptococcus suis is a major swine pathogen worldwide and causes considerable economic losses in the swine industry. S. suis is also an emerging zoonotic agent, mainly in Asia. In pigs and humans, S. suis can cause septicemia, pneumonia, endocarditis, arthritis, and meningitis with irreversible sequelae. Identification and characterization of the virulence factors produced by S. suis are major advances in the understanding of the pathogenesis of S. suis infections and has therefore opened promising avenues for vaccine development against this pathogen. This literature review aimed to update the current knowledge of the virulence mechanisms of S. suis and of the vaccination strategies tested until now.
Topics: Animals; Anti-Bacterial Agents; Asia; Bacterial Proteins; Bacterial Vaccines; Drug Resistance, Multiple, Bacterial; Global Health; Humans; Serogroup; Streptococcal Infections; Streptococcus suis; Swine; Swine Diseases; Vaccination; Virulence; Zoonoses
PubMed: 29122409
DOI: 10.1016/j.medmal.2017.10.001 -
Applied Microbiology and Biotechnology Nov 2018Streptococcus suis (S. suis) is a major swine pathogen and an important zoonotic agent. Like most pathogens, the ability of S. suis to form biofilms plays a significant... (Review)
Review
Streptococcus suis (S. suis) is a major swine pathogen and an important zoonotic agent. Like most pathogens, the ability of S. suis to form biofilms plays a significant role in its virulence and drug resistance. A better understanding of the mechanisms involved in biofilm formation by S. suis as well as of the methods to efficiently remove and kill biofilm-embedded bacteria can be of high interest for the prevention and treatment of S. suis infections. The aim of this literature review is to update our current knowledge of S. suis biofilm formation, regulatory mechanisms, drug-resistance mechanisms, and disinfection strategies.
Topics: Animals; Biofilms; Disinfection; Drug Resistance, Bacterial; Humans; Streptococcal Infections; Streptococcus suis; Swine; Swine Diseases; Virulence; Zoonoses
PubMed: 30209548
DOI: 10.1007/s00253-018-9356-z -
Trends in Microbiology Jul 2017Streptococcus suis is an important swine pathogen that can be transmitted to humans by contact with diseased animals or contaminated raw pork products. This pathogen... (Review)
Review
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 research developments, cautiously inventoried in this review, have revealed over 100 'putative virulence factors or traits' (surface-associated or secreted components, regulatory genes or metabolic pathways), of which at least 37 have been claimed as being 'critical' for virulence. In this review we discuss the current contradictions and controversies raised by this explosion of virulence factors and the future directions that may be conceived to advance and enlighten research on S. suis pathogenesis.
Topics: Animals; Disease Models, Animal; Humans; Mutagenesis; Polysaccharides, Bacterial; Red Meat; Streptococcal Infections; Streptococcus suis; Swine; Virulence; Virulence Factors
PubMed: 28274524
DOI: 10.1016/j.tim.2017.02.005 -
Journal of Microbiology, Immunology,... Aug 2019Streptococcus suis (S. suis) type 2 (SS2) is an important zoonotic pathogen that causes swine streptococcosis, a widespread infectious disease that occurs in pig... (Review)
Review
Streptococcus suis (S. suis) type 2 (SS2) is an important zoonotic pathogen that causes swine streptococcosis, a widespread infectious disease that occurs in pig production areas worldwide and causes serious economic losses in the pork industry. Hosts recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs) to activate both innate and acquired immune responses. However, S. suis has evolved multiple mechanisms to escape host defenses. Pathogenic proteins, such as enolase, double-component regulatory systems, factor H-combining proteins and other pathogenic and virulence factors, contribute to immune escape by evading host phagocytosis, reactive oxygen species (ROS), complement-mediated immune destruction, etc. SS2 can prevent neutrophil extracellular trap (NET) formation to avoid being trapped by porcine neutrophils and disintegrate host immunoglobulins via IgA1 hydrolases and IgM proteases. Currently, the pathogenesis of arthritis and meningitis caused by SS2 infection remains unclear, and further studies are necessary to elucidate it. Understanding immune evasion mechanisms after SS2 infection is important for developing high-efficiency vaccines and targeted drugs.
Topics: Animals; Complement Factor H; Host-Pathogen Interactions; Humans; Immune Evasion; Neutrophils; Phagocytosis; Serogroup; Streptococcal Infections; Streptococcus suis; Swine; Virulence Factors
PubMed: 30954397
DOI: 10.1016/j.jmii.2019.03.003 -
Applied Microbiology and Biotechnology Sep 2018Quorum sensing (QS) is an important protective mechanism that allows bacteria to adapt to its environment. A limited number of signal molecules play the key role of... (Review)
Review
Quorum sensing (QS) is an important protective mechanism that allows bacteria to adapt to its environment. A limited number of signal molecules play the key role of transmitting information in this mechanism. Signals are transmitted between individual bacterium through QS systems, resulting in the expression of specific genes. QS plays an important role in a variety of bacterial processes, including drug resistance, biofilm formation, motility, adherence, and virulence. Most Gram-positive and Gram-negative bacteria possess QS systems, mainly the LuxS/AI-2-mediated QS system. Evidence has been brought that LuxS/AI-2 system controls major virulence determinants in Streptococcus suis and, as such, the ability of this bacterial species to cause infections in humans and pigs. Understanding the S. suis LuxS/AI-2 system may open up novel avenues for decreasing the drug resistance and infectivity of S. suis. This article focuses on the progress made to date on the S. suis LuxS/AI-2-mediated QS system.
Topics: Adaptation, Physiological; Animals; Bacterial Adhesion; Bacterial Proteins; Biofilms; Carbon-Sulfur Lyases; Gene Expression Regulation, Bacterial; Homoserine; Humans; Lactones; Quorum Sensing; Signal Transduction; Streptococcus suis; Virulence
PubMed: 29938319
DOI: 10.1007/s00253-018-9170-7 -
Virulence May 2014Streptococcus 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... (Review)
Review
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.
Topics: Animals; Communicable Diseases, Emerging; Humans; Streptococcal Infections; Streptococcus suis; Swine; Swine Diseases; Zoonoses
PubMed: 24667807
DOI: 10.4161/viru.28595 -
Annals of Agricultural and... Mar 2018is a re-emerging zoonotic pathogen that may cause severe disease, mostly meningitis, in pigs and in humans having occupational contact with pigs and pork, such as... (Review)
Review
is a re-emerging zoonotic pathogen that may cause severe disease, mostly meningitis, in pigs and in humans having occupational contact with pigs and pork, such as farmers, slaughterhose workers and butchers. The first stage of the pathogenic process, similar in pigs and humans, is adherence to and colonisation of mucosal and/or epithelial surface(s) of the host. The second stage is invasion into deeper tissue and extracellular translocation of bacterium in the bloodstream, either free in circulation or attached to the surface of monocytes. If present in blood fails to cause fatal septicaemia, it is able to progress into the third stage comprising penetration into host's organs, mostly by crossing the blood-brain barrier and/or blood-cerebrospinal fluid barrier to gain access to the central nervous system (CNS) and cause meningitis. The fourth stage is inflammation that plays a key role in the pathogen esis of both systemic and CNS infections caused by . The pathogen may induce the overproduction of pro-inflammatory cytokines that cause septic shock and/or the recruitment and activation of different leukocyte populations, causing acute inflammation of the CNS. can also evoke - through activation of microglial cells, astrocytes and possibly other cell types - a fulminant inflammatory reaction of the brain which leads to intracranial complications, including brain oedema, increased intracranial pressure, cerebrovascular insults, and deafness, as a result of cochlear sepsis. In all stages of the pathogenic process, interacts with many types of immunocompetent host's cells, such as polymorphonuclear leukocytes, mononuclear macrophages, lymphocytes, dendritic cells and microglia, using a range of versatile virulence factors for evasion of the innate and adaptive immune defence of the host, and for overcoming environmental stress. It is estimated that produces more than 100 different virulence factors that could be classified into 4 groups: surface components or secreted elements, enzymes, transcription factors or regulatory systems and transporter factors or secretion systems. A major virulence factor is capsular polysaccharide (CPS) that protects bacteria from phagocytosis. However, it hampers adhesion to and invasion of host's cells, release of inflammatory cytokines and formation of the resistant biofilm which, in many cases, is vital for the persistence of bacteria. It has been demonstrated that the arising by mutation unencapsulated clones, which are more successful in penetration to and propagation within the host's cells, may coexist in the organism of a single host together with those that are encapsulated. Both 'complementary' clones assist each other in the successful colonization of host's tissues and persistence therein. has an open pan-genome characterized by a frequent gene transfer and a large diversity. Of the genetic determinants of pathogenicity, the most important are pathogenicity islands (PAI), in particular, a novel DNA segment of 89 kb length with evident pathogenic traits that has been designated as 89K PAI. It has been estimated that more than one-third of the virulence factors is associated with this PAI. It has been proved that the virulent strains possess smaller genomes, compared to avirulent ones, but more genes associated with virulence. Overall, the evolution of the species most probably aims towards increased pathogenicity, and hence the most significant task of the current research is an elaboration of a vaccine, efficient both for humans and pigs.
Topics: Agricultural Workers' Diseases; Animals; Humans; Occupational Exposure; Streptococcal Infections; Streptococcus suis; Swine; Swine Diseases; Virulence; Virulence Factors; Zoonoses
PubMed: 29575852
DOI: 10.26444/aaem/85651 -
The Southeast Asian Journal of Tropical... Dec 2004Streptococcus suis may be the second most common cause of adult streptococcal meningitis. The clinical and epidemiological data of S. suis meningitis are occasionally... (Review)
Review
Streptococcus suis may be the second most common cause of adult streptococcal meningitis. The clinical and epidemiological data of S. suis meningitis are occasionally reviewed. To date, there have been only two large case series from Hong Kong and the Netherlands. We describe twelve cases of S. suis meningitis who were admitted to Chulalongkorn University Hospital, Bangkok, during a 6-year period between 1997 and 2002. A comparative review of case reports of S. suis meningitis in Thailand, Hong Kong, and the Netherlands is presented and revealed no significant differences between the three series. However, the cases from Thailand and Hong Kong had a significantly greater number of associated skin and soft tissue infections. Clinically, S. suis meningitis may appear acute or with a more chronic course.
Topics: Adult; Aged; Animals; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Serotyping; Streptococcal Infections; Streptococcus suis; Swine; Thailand
PubMed: 15916083
DOI: No ID Found -
The Lancet. Infectious Diseases Mar 2007Streptococcus suis is a major porcine pathogen worldwide, and can be transmitted to human beings by close contact with sick or carrier pigs. S suis causes meningitis,... (Review)
Review
Streptococcus suis is a major porcine pathogen worldwide, and can be transmitted to human beings by close contact with sick or carrier pigs. S suis causes meningitis, septicaemia, endocarditis, arthritis, and septic shock in both pigs and human beings, and mortality is high. Human infection with S suis occurs mainly among certain risk groups that have frequent exposure to pigs or pork. Outbreaks of human S suis infection are uncommon, although several outbreaks have occurred in China in recent years. In July, 2005, the largest outbreak of human S suis infection occurred in Sichuan province, China, where 204 people were infected and 38 of them died. There have been 409 cases of human S suis infection worldwide, most of which have occurred in China, Thailand, and the Netherlands, and these infections have led to 73 deaths. This review provides background information on the biology and molecular characteristics of this Gram-positive bacterium, and describes the clinical signs, pathology, epidemiology, diagnosis, and treatment of human infection with S suis.
Topics: Animals; Humans; Streptococcal Infections; Streptococcus suis; Zoonoses
PubMed: 17317601
DOI: 10.1016/S1473-3099(07)70001-4 -
Microbiology Spectrum Feb 2022To investigate the presence and location of (T) in clinical Streptococcus suis isolates and explore the transmission ability and fitness cost of (T)-carrying mobile...
To investigate the presence and location of (T) in clinical Streptococcus suis isolates and explore the transmission ability and fitness cost of (T)-carrying mobile genetic elements among S. suis isolates, MICs were determined by broth microdilution. The presence of (T) in S. suis was detected by PCR. The genetic environment of (T) in S. suis was explored by whole-genome sequencing (WGS) analysis. Intraspecies and interspecies transmission were examined by electrotransformation. The fitness cost associated with the carriage of an (T)-harboring plasmid or an integrative and conjugative element (ICE) was examined by competition experiments. Of 237 nonduplicate strains, (T) was detected in 2 S. suis strains (SC262-ST954 and SC117-ST1314), with its location on a 5,125-bp plasmid in S. suis SC262 and on a 64,013-bp ICESC117 in S. suis SC117, respectively. Both the (T)-carrying plasmid pSC262 and the ICESC117 were transmissible by transformation. Plasmid pSC262 can replicate and express macrolide-lincosamide resistance in heterologous hosts, including S. aureus and S. pneumoniae. Both the (T)-carrying plasmid and the ICE posed a fitness cost to the host S. suis isolate. To the best of our knowledge, this is the first report of the macrolide-lincosamide-streptogramin B resistance gene (T) in S. suis. Its location on a plasmid or an ICE will aid in its transmission. The low detection rate of (T) gene among the S. suis population might be due to the fitness cost of the (T)-carrying plasmid and ICE. Macrolide and lincosamide resistance due to the presence of (T) have posed a challenge for the treatment of Gram-positive pathogens. Although the low detection rate of (T) gene among the S. suis population due to the fitness cost of the (T)-carrying plasmid and ICE, the presence of (T) in S. suis and its potential transmission to other Gram-positive pathogens will be of important significance.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Humans; Lincosamides; Macrolides; Microbial Sensitivity Tests; Staphylococcus aureus; Streptococcal Infections; Streptococcus pneumoniae; Streptococcus suis
PubMed: 35019703
DOI: 10.1128/spectrum.01657-21