A5020473030- Streptococcal Infections and Treatments
- Antimicrobial Resistance in Staphylococcus
- Neonatal and Maternal Infections
- Infective Endocarditis Diagnosis and Management
- Bacterial Identification and Susceptibility Testing
- Otolaryngology and Infectious Diseases
- Inflammasome and immune disorders
- Plant Pathogenic Bacteria Studies
- Bacterial Genetics and Biotechnology
- Infections and bacterial resistance
- RNA and protein synthesis mechanisms
- Bacteriophages and microbial interactions
- Immune Response and Inflammation
- Pneumonia and Respiratory Infections
- RNA Interference and Gene Delivery
- Neonatal Health and Biochemistry
- Bacterial Infections and Vaccines
- Botulinum Toxin and Related Neurological Disorders
- Autophagy in Disease and Therapy
- Fungal Infections and Studies
- Ocular Diseases and Behçet’s Syndrome
National Institute of Infectious Diseases
2016-2025
National Institutes of Health
2010-2015
Hiroshima University
1999
Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of and multiorgan failure; it has high mortality rate. Although number studies have attempted to determine crucial factors behind STSS, responsible genes in group A Streptococcus not been clarified. We previously reported that mutations csrS/csrR genes, two-component negative regulator system for multiple virulence pyogenes, are found among isolates from STSS patients. In present study,...
ObjectivesStreptococcal toxic shock syndrome (STSS) is caused by group A Streptococcus (GAS; pyogenes) strains. In Japan, the number of STSS cases has decreased; however, underlying reason remains unclear. Moreover, information on distribution and prevalence specific emm types in scarce. Hence, we investigated for decreased Japan.MethodsWe genotyped 526 GAS isolates obtained from patients with between 2019 2022. The distributions each year were compared.ResultsThe emm1 type was predominant,...
Streptococcus pyogenes causes mild human infections as well life-threatening invasive diseases. Since the mutations known to enhance virulence date account for only half of severe infections, additional mechanisms/mutations need be identified. Here, we conducted a genome-wide association study emm 89 S. strains comprehensively identify pathology-related bacterial genetic factors (SNPs, indels, genes, or k-mers). Japanese ( n =311) and global =666) cohort studies isolated from non-invasive...
Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on Infectious Disease Control law are mandatory for cases STSS caused β-haemolytic streptococcus. mainly group A streptococcus (GAS). Although an average 60-70 GAS-induced reported annually, 143 were recorded in 2011. To determine reason behind this marked increase, we emm genotype 249...
ABSTRACT In Japan, more than 10% of streptococcal toxic shock-like syndrome (TSLS) cases have been caused by Streptococcus pyogenes M3/T3 isolates since the first reported TSLS case in 1992. Most from or severe invasive infection during 1992 to 2001 and those noninvasive this period are indistinguishable pulsed-field gel electropherograms. The longest fragments these recent were 300 kb size, whereas recovered before 1973 260 size. These 260- 300-kb hybridized each other, suggesting...
The number of patients with severe invasive group-G streptococcal ( Streptococcus dysgalactiae subsp. equisimilis ) infections has been increasing in Japan. emm genotypes and Sma I-digested pulsed-field gel electrophoresis DNA profiles were variable among the strains isolated, suggesting there not clonal expansion a specific subpopulation strains. However, all carried scpA , ska slo sag genes, some which may be involved pathogenesis disease.
Group A streptococcus (GAS) causes variety of diseases ranging from common pharyngitis to life-threatening severe invasive diseases, including necrotizing fasciitis and streptococcal toxic shock-like syndrome. The characteristic GAS infections has been thought attribute genetic changes in bacteria, however, no clear evidence shown due lack an intriguingly study using serotype-matched isolates clinical infections. In addition, rare outbreaks their distinctive pathology which infectious foci...
Significance Group A Streptococcus (GAS) causes invasive streptococcal infections in humans, resulting high mortality. Thus, GAS is also known as “killer bacteria” or “flesh-eating bacteria.” The mechanism by which the immune system recognizes this potent pathogen remains elusive. In study, we showed that innate receptor Mincle (macrophage inducible C-type lectin) plays pivotal roles against infection through recognition of monoglucosyldiacylglycerol (MGDG), a component lipoteichoic acid...
The flagellar operons of Salmonella are divided into three classes with respect to their transcriptional hierarchy. Expression the class 2 requires 1 gene products, FlhD and FlhC, is increased by mutation in flgM gene, which encodes a 3-specific anti-sigma factor. Here we report identification two novel regulatory genes for transcription. Presence fliZ fliT on multicopy plasmids enhanced inhibited, respectively, transcription from chromosomal promoter. Disruption chromosome decreased...
Streptococcus pyogenes causes mild human infections as well life-threatening invasive diseases. Since the mutations known to enhance virulence date account for only half of severe infections, additional mechanisms/mutations need be identified. Here, we conducted a genome-wide association study emm 89 S. strains comprehensively identify pathology-related bacterial genetic factors (SNPs, indels, genes, or k-mers). Japanese ( n =311) and global =666) cohort studies isolated from non-invasive...
Streptococcal toxic shock syndrome (STSS) is a severe invasive infection that has high mortality rate. It mainly caused by Streptococcus pyogenes. Nevertheless, STSS also known to be group G identified as dysgalactiae subsp. equisimilis (SDSE). Invasive SDSE predominantly occurs in elderly individuals but extremely rare children. Furthermore, reports on are limited; hence, the clinical aspects and type of mature M protein (emm) gene involved unknown. A five-year-old girl with Down syndrome,...
ABSTRACT Clinical isolates of Streptococcus pyogenes are usually classified using emm and multilocus sequence typing (MLST). Recently, whole genome sequencing (WGS) has been employed for MLST analysis. WGS data provides additional information on the presence virulence factor genes. To enable researchers unfamiliar with bioinformatics to analyze S. , we opened an online tool named GAS‐J, which automatically outputs types, types (STs), carriage genes, phylogenetic trees. The accepts raw...
Abstract Streptococcus pyogenes causes mild human infections as well life-threatening invasive diseases. Since the mutations known to enhance virulence date account for only half of severe infections, additional mechanisms/mutations need be identified. Here, we conducted a genome-wide association study emm89 S. strains comprehensively identify pathology-related bacterial genetic factors (SNPs, indels, genes, or k-mers). Japanese (n=311) and global (n=666) cohort studies isolated from...
The fliA gene encodes the flagellum-specific sigma factor σ28 in Salmonella typhimurium. transcription vivo and vitro of this was analysed it found that there are two promoters for expression One is a class 2 promoter which recognized by σ70-RNA polymerase presence FlhD FlhC activator proteins. other 3 σ28-RNA polymerase. Therefore, operon under dual positive control from FlhD/FlhC FliA itself. nucleotide sequence downstream determined. contains ORFs following gene. On basis their homology,...
Flagellar class 3 operons of Escherichia coli and Salmonella are transcribed by RNA polymerase containing σ28. The consensus sequence the σ28-dependent pro-moters was believed to be TAAA N15 GCCGATAA. In this study, we found that E. genome contains a large number sequences homologous consen-sus. However, showed they do not always exert promoter activity. We compare more carefully flagellar promot-ers propose revised structure promoters as TAAAGTTT N11
Thirteen Streptococcus dysgalactiae subsp. equisimilis isolates possessing Lancefield's group A antigen recovered from people in Japan during 2000 to 2004 were genotyped. The results indicate that a conserved clone has persisted and spread within Japan, two different emm types observed members of this clone.
Cytokine-activated neutrophils are known to be essential for protection against group A Streptococcus infections. However, during severe invasive infections that accompanied by neutropenia, it remains unclear which factors protective such infections, and cell population is the source of them. Here we show mice infected with isolates, but not non-invasive exhibit high concentrations plasma interferon-γ early stage infection. Interferon-γ necessary protect mice, produced a novel...
The Salmonella flagellar operons are divided into three classes with reference to their relative positions in the transcriptional hierarchy. Expression of class 2 requires 1 gene products, FlhD and FlhC, is enhanced by an unknown mechanism presence 3-specific sigma factor, FliA, absence its cognate anti-sigma FlgM. In this study, start site mapping was performed primer extension analysis for five operons, flgA, flgB, flhB, fliE fliL. all cases, one or a few major sites were identified. These...
Seven cases of Streptococcus suis infection in Japan during 1994 and 2006 were summarized. All had porcine exposure five them hand skin injury the exposure. Five presented symptoms meningitis, three sepsis, one resulted sudden death. isolated S. belonged to Lancefield's group D serotype 2. They susceptible penicillin G, ampicillin, cefotaxime, ciprofloxacin. However, six resistant both erythromycin clindamycin, four also minocycline. Multilocus sequence typing isolates showed that they type...
We previously reported that type M3 group A streptococcus (GAS) showed a wide range of 50% lethal dose values in mice. Analysis using DNA arrays indicated the most virulent strain, M3-f, expressed significantly higher levels products several virulence genes than did other isolates. Sequencing csrS, csrR, luxS, and rgg isolates M-3f csrR gene contained specific point mutation. Disruption wild-type (wt) an strain increased its expression hyaluronic acid, whereas complementation with wt but not...
The incidence of streptococcal toxic shock syndrome (STSS) due to group B Streptococcus (GBS) has been increasing annually in Japan and is becoming a serious challenge. Furthermore, recent years, penicillin- or clindamycin-resistant strains used treating have reported. However, no report analyzed >100 isolates causing syndrome. Therefore, we aimed perform serotyping antimicrobial susceptibility testing 268 isolated from cases involving nonpregnant adult patients between 2014 2021. most...
We assessed antimicrobial susceptibility against 211 Streptococcus pyogenes strains isolated from patients with severe invasive group A streptococcal infections. Overall, 3.8, 1.4, and 0.5% of the isolates were resistant to erythromycin, clindamycin, telithromycin, ciprofloxacin, respectively, 10.4% had intermediate resistance ciprofloxacin. All susceptible ampicillin cefotaxime.
SUMMARY We surveyed emm genotypes of group A streptococcus (GAS) isolates from patients with severe invasive streptococcal infections during 2001–2005 and compared their prevalence that the preceding 5 years. Genotype emm1 remained dominant throughout 2001 to 2005, but frequency rate this type decreased earlier period. Various other types have appeared in recent years indicating alterations prevalent strains causing infections. The cover new 26-valent GAS vaccine fell 93·5% for 1996–2000...