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Veterinary Research Nov 2022Streptococcus suis is a zoonotic agent that causes sepsis and meningitis in pigs and humans. S. suis infections are responsible for large economic losses in pig... (Review)
Review
Streptococcus suis is a zoonotic agent that causes sepsis and meningitis in pigs and humans. S. suis infections are responsible for large economic losses in pig production. The lack of effective vaccines to prevent the disease has promoted the extensive use of antibiotics worldwide. This has been followed by the emergence of resistance against different classes of antibiotics. The rates of resistance to tetracyclines, lincosamides, and macrolides are extremely high, and resistance has spread worldwide. The genetic origin of S. suis resistance is multiple and includes the production of target-modifying and antibiotic-inactivating enzymes and mutations in antibiotic targets. S. suis genomes contain traits of horizontal gene transfer. Many mobile genetic elements carry a variety of genes that confer resistance to antibiotics as well as genes for autonomous DNA transfer and, thus, S. suis can rapidly acquire multiresistance. In addition, S. suis forms microcolonies on host tissues, which are associations of microorganisms that generate tolerance to antibiotics through a variety of mechanisms and favor the exchange of genetic material. Thus, alternatives to currently used antibiotics are highly demanded. A deep understanding of the mechanisms by which S. suis becomes resistant or tolerant to antibiotics may help to develop novel molecules or combinations of antimicrobials to fight these infections. Meanwhile, phage therapy and vaccination are promising alternative strategies, which could alleviate disease pressure and, thereby, antibiotic use.
Topics: Humans; Swine; Animals; Streptococcus suis; Streptococcal Infections; Anti-Bacterial Agents; Macrolides; Swine Diseases
PubMed: 36371221
DOI: 10.1186/s13567-022-01111-3 -
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 -
Nature Communications Apr 2023Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus....
Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus. Serine/threonine kinases (STKs, e.g. Stk1) can also regulate CPS synthesis, but the underlying mechanisms are unclear. Here, we identify a protein (CcpS) that is phosphorylated by Stk1 and modulates the activity of phosphatase CpsB in Streptococcus suis, thus linking Stk1 to CPS synthesis. The crystal structure of CcpS shows an intrinsically disordered region at its N-terminus, including two threonine residues that are phosphorylated by Stk1. The activity of phosphatase CpsB is inhibited when bound to non-phosphorylated CcpS. Thus, CcpS modulates the activity of phosphatase CpsB thereby altering CpsD phosphorylation, which in turn modulates the expression of the Wzx-Wzy pathway and thus CPS production.
Topics: Phosphorylation; Streptococcus suis; Polysaccharides, Bacterial; Protein Serine-Threonine Kinases; Phosphoric Monoester Hydrolases; Bacterial Capsules
PubMed: 37120581
DOI: 10.1038/s41467-023-38210-4 -
Expert Review of Vaccines 2015Streptococcus suis is a major swine pathogen and an emerging zoonotic agent of human meningitis and streptococcal toxic shock-like syndrome. S. suis is a... (Review)
Review
Streptococcus suis is a major swine pathogen and an emerging zoonotic agent of human meningitis and streptococcal toxic shock-like syndrome. S. suis is a well-encapsulated pathogen and multiple serotypes have been described based on the capsular polysaccharide antigenic diversity. In addition, high genotypic, phenotypic and geographic variability exits among strains within the same serotype. Besides, S. suis uses an arsenal of virulence factors to evade the host immune system. Together, these characteristics have challenged the development of efficacious vaccines to fight this important pathogen. In this careful and comprehensive review, clinical field information and experimental data have been compiled and compared for the first time to give a precise overview of the current status of vaccine development against S. suis. The candidate antigens and vaccine formulations under research are examined and the feasibility of reaching the goal of a "universal" cross-protective S. suis vaccine discussed.
Topics: Animals; Antibodies, Bacterial; Humans; Meningitis, Bacterial; Shock, Septic; Streptococcal Vaccines; Streptococcus suis; Swine; Swine Diseases; Vaccination; Vaccines, Attenuated; Vaccines, Subunit
PubMed: 26468755
DOI: 10.1586/14760584.2015.1101349 -
Emerging Infectious Diseases Dec 2019Streptococcus suis is an emerging agent of zoonotic bacterial meningitis in Asia. We describe the epidemiology of S. suis cases and clinical signs and microbiological...
Streptococcus suis is an emerging agent of zoonotic bacterial meningitis in Asia. We describe the epidemiology of S. suis cases and clinical signs and microbiological findings in persons with meningitis in Bali, Indonesia, using patient data and bacterial cultures of cerebrospinal fluid collected during 2014-2017. We conducted microbiological assays using the fully automatic VITEK 2 COMPACT system. We amplified and sequenced gene fragments of glutamate dehydrogenase and recombination/repair protein and conducted PCR serotyping to confirm some serotypes. Of 71 cases, 44 were confirmed as S. suis; 29 isolates were serotype 2. The average patient age was 48.1 years, and 89% of patients were male. Seventy-seven percent of patients with confirmed cases recovered without complications; 11% recovered with septic shock, 7% with deafness, and 2% with deafness and arthritis. The case-fatality rate was 11%. Awareness of S. suis infection risk must be increased in health promotion activities in Bali.
Topics: Adult; Aged; Bacterial Proteins; Biomarkers; DNA Restriction Enzymes; Female; Geography, Medical; History, 21st Century; Humans; Indonesia; Male; Meningitis, Pneumococcal; Middle Aged; Phylogeny; Polymerase Chain Reaction; Public Health Surveillance; Serotyping; Streptococcus suis; Symptom Assessment
PubMed: 31742523
DOI: 10.3201/eid2512.181709 -
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 -
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 -
Current Issues in Molecular Biology 2019() is an important zoonotic pathogen that causes huge economic losses in the pig industry, as well as severe illness and even death in humans. The outbreak of human... (Review)
Review
() is an important zoonotic pathogen that causes huge economic losses in the pig industry, as well as severe illness and even death in humans. The outbreak of human infection of in China in 2005 led to significant human morbidity and death, prompting an increase in global studies of . In recent years, important advances have been made regarding the etiology, genomics, excavation of virulence genes, and vaccine research in . A number of countries and regions have identified their predominantly serotypes. The development of genome sequencing technology has laid an important foundation for the study of pathogenic mechanisms. For example, 89K PAI was found in representative virulence strains in China, and several studies have been carried out to confirm multiple genes which carries are closely related to virulence. Also, the functions of some regulatory genes represented by the two-component signal transduction system have been analyzed. The development of inactivated vaccines, natural avirulent vaccines, gene-deletion attenuated vaccines, subunit vaccines, and glycoconjugate vaccines have greatly contributed to the prevention and control of the disease in the future. This article aims to summarize the research progress to provide directions for future research and the prevention of .
Topics: Animals; China; Disease Outbreaks; Gene Expression Regulation, Bacterial; Gene Regulatory Networks; Genes, Bacterial; Genome, Bacterial; Humans; Prevalence; Signal Transduction; Streptococcal Infections; Streptococcal Vaccines; Streptococcus suis; Swine; Swine Diseases; Vaccines, Attenuated; Vaccines, Subunit; Virulence
PubMed: 31166178
DOI: 10.21775/cimb.032.473 -
Virulence Dec 2023is a bacterium that can cause infections in pigs and humans. Although oxidative stress is common occurrence during bacterial growth and infection, the regulation...
is a bacterium that can cause infections in pigs and humans. Although oxidative stress is common occurrence during bacterial growth and infection, the regulation networks of under oxidative stress remain poorly understood. To address this, we utilized RNA-Seq to reveal the transcriptional landscape of in response to HO stress. We identified novel genes responsible for resistance to oxidative stress, including those involved in DNA repair or protection, and essential for the biosynthesis of amino acids and nucleic acids. In addition, we found that a novel aquaporin, Aagp, belonging to atypical aquaglyceroporins and widely distributed in diverse serotypes, plays a crucial role during HO stress. By performing oxidative stress assays and measuring the intracellular HO concentrations of the wild-type strain and mutants during HO stress, we found that Aagp facilitated HO efflux. Additionally, we found that Aagp might be involved in glycerol transport, as shown by the growth inhibition and HO production in the presence of glycerol. Mice infection experiments indicated that Aagp contributed to virulence. This study contributes to understanding the mechanism of oxidative stress response, pathogenesis, and the function of aquaporins in prokaryotes.
Topics: Humans; Animals; Mice; Swine; Hydrogen Peroxide; Streptococcus suis; Glycerol; Virulence; Aquaporins
PubMed: 37621097
DOI: 10.1080/21505594.2023.2249789 -
Microbial Pathogenesis Aug 2023Streptococcus suis (S. suis) regulates biofilm formation through LuxS/AI-2 quorum sensing system, increasing drug resistance and exacerbating infection. The...
Streptococcus suis (S. suis) regulates biofilm formation through LuxS/AI-2 quorum sensing system, increasing drug resistance and exacerbating infection. The anti-hyperglycaemic agent metformin has anti-bacterial and anti-biofilm activities. This study aimed to investigate the anti-biofilm and anti-quorum sensing activity of metformin in S. suis. We first determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of metformin on S. suis. The results indicated that metformin showed no obvious inhibitory or bactericidal effect. Crystal violet staining showed that metformin significantly inhibited the formation of S. suis biofilm at sub-MIC concentration, which was also confirmed by scanning electron microscopy. Then, we quantified the AI-2 signal molecules in S. suis, and the results showed that metformin had a significant inhibitory effect on the production of AI-2 signal in S. suis. Inhibition of enzyme activity and molecular docking experiments showed that metformin has a significant binding activity to LuxS protein. In addition, qRT-PCR results showed that metformin significantly down-regulated the expression of AI-2 synthesis-related genes luxS and pfs, and adhesion-related genes luxS, pfs, gapdh, sly, fbps, and ef. Western blotting also showed that metformin significantly reduced the expression of LuxS protein. Our study suggests that metformin seems to be a suitable candidate for the inhibition of S. suis LuxS/AI-2 QS system and prevention of biofilm formation, which provided a new idea for the prevention and control of S. suis.
Topics: Streptococcus suis; Molecular Docking Simulation; Homoserine; Bacterial Proteins; Quorum Sensing; Biofilms; Carbon-Sulfur Lyases; Lactones
PubMed: 37263449
DOI: 10.1016/j.micpath.2023.106183