Genetic characteristics of invasive pneumococcal disease-derived Streptococcus pneumoniae of serogroup 24 isolated in Tokyo, Japan.

Background: Since the introduction of the national routine vaccination program against Streptococcus pneumoniae in Japan from the early 2010s, the incidence of invasive pneumococcal disease (IPD) caused by non-vaccine serotypes has increased. This study focused on non-vaccine serogroup 24 strains derived from IPD and aimed to clarify their genetic characteristics.

Methods: Between 2013 and 2022, 121 strains identified as serogroup 24 in patients with IPD were collected and applied to multilocus sequence typing and next-generation sequencing.

Characterization of pig tonsils as niches for the generation of Streptococcus suis diversity.

Streptococcus suis is a gram-positive bacterium that causes meningitis, septicemia, endocarditis, and other disorders in pigs and humans. We obtained 42 and 50 S. suis isolates from lesions of porcine endocarditis and palatine tonsils, respectively, of clinically healthy pigs in Japan; we then determined their sequence types (STs) by multilocus sequence typing (MLST), cps genotypes, serotypes, and presence of classical major virulence-associated marker genes (mrp, epf, and sly).

Serotype Distribution and Antimicrobial Resistance of Streptococcus agalactiae Isolates in Nonpregnant Adults with Streptococcal Toxic Shock Syndrome in Japan in 2014 to 2021.

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, in recent years, penicillin- or clindamycin-resistant strains used in treating streptococcal toxic shock syndrome have been reported. However, no report analyzed >100 isolates of group B Streptococcus causing streptococcal toxic shock syndrome.

Natural mutation in the regulatory gene (srrG) influences virulence-associated genes and enhances invasiveness in Streptococcus dysgalactiae subsp. equisimilis strains isolated from cases of streptococcal toxic shock syndrome.

Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) has emerged as an important cause of severe invasive infections including streptococcal toxic shock syndrome (STSS). The present study aimed to identify genes involved in differences in invasiveness between STSS and non-invasive SDSE isolates.

Methods: STSS and non-invasive SDSE isolates were analysed to identify csrS/csrR mutations, followed by a comparative analysis of genomic sequences to identify mutations in other genes.

Molecular characterization and antimicrobial resistance of group A streptococcus isolates in streptococcal toxic shock syndrome cases in Japan from 2013 to 2018.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and puerperal sepsis and shows high mortality. Its primary cause is group A streptococcus (GAS, Streptococcus pyogenes). In this study, we genotyped the cell-surface M virulence protein gene (emm) from 621 GAS isolates obtained from patients with STSS in Japan in 2013-2018 and performed antimicrobial susceptibility testing using the broth microdilution method.

T serotyping of group a streptococcus isolated from patients with pharyngitis or streptococcal toxic shock syndrome in Japan between 2005 and 2017.

Streptococcus pyogenes (group A streptococcus; GAS) is an important gram-positive human pathogen capable of causing diseases ranging from mild superficial skin and pharyngeal infections to more severe invasive diseases, including streptococcal toxic shock syndrome (STSS). GAS produces a T protein, and T serotyping has considerable discriminatory power for epidemiological characterization of GAS. To clarify the relationship between STSS and pharyngitis in Japan, we examined the T serotypes of GAS strains isolated from clinical specimens of streptococcal infections (STSS, 951 isolates; pharyngitis, 16268 isolates) from 2005 to 2017.

IMP-68, a Novel IMP-Type Metallo-β-Lactamase in Imipenem-Susceptible Klebsiella pneumoniae.

We recently detected a novel variant of an IMP-type metallo-β-lactamase gene () from meropenem-resistant but imipenem-susceptible TA6363 isolated in Tokyo, Japan. encodes a Ser262Gly point mutant of IMP-11, and transformation experiments showed that increased the MIC of carbapenems in recipient strains, whereas the MIC of imipenem was not greatly increased relative to that of other carbapenems, including meropenem. Kinetics experiments showed that IMP-68 imipenem-hydrolyzing activity was lower than that for other carbapenems, suggesting that the antimicrobial susceptibility profile of TA6363 originated from IMP-68 substrate specificity.

FRI-4 carbapenemase-producing Enterobacter cloacae complex isolated in Tokyo, Japan.

Objectives: A carbapenem-resistant Enterobacter cloacae complex isolated in Tokyo, Japan, produced a carbapenemase that was detected by a Carba NP test and a modified carbapenem inactivation method, but none of the 'Big Five' carbapenemase genes was detected by PCR. This study aimed to identify the carbapenemase.

Methods: Carbapenemase genes were screened by WGS.

Spontaneous mutations in Streptococcus pyogenes isolates from streptococcal toxic shock syndrome patients play roles in virulence.

Streptococcus pyogenes (group A Streptococcus; GAS) is a widespread human pathogen and causes streptococcal toxic shock syndrome (STSS). STSS isolates have been previously shown to have high frequency mutations in the csrS/csrR (covS/covR) and/or rgg (ropB) genes, which are negative regulators of virulence. However, these mutations were found at somewhat low frequencies in emm1-genotyped isolates, the most prevalent STSS genotype.

[Isolation of Neisseria elongata subsp. elongata Isolated from an Acute Myelogenous Leukemia Patient].

Gram-negative cocci with a rod-like shape were isolated from a blood sample of a patient with acute myelogenous leukemia (AML). The 16S rRNA sequence of the isolate was similar to that of Neisseria elongata. Because previous reports about N.

Evaluation of streptococcal toxic shock-like syndrome caused by group B streptococcus in adults in Japan between 2009 and 2013.

Infection with Streptococcus agalactiae has long been recognized in infants. In recent years, S. agalactiae is an important cause of morbidity and mortality among adults and among those with underlying medical condition.

Meningococcemia due to the 2000 Hajj-associated outbreak strain (Serogroup W-135 ST-11) with immunoreactive complications.

We present the first reported case of systemic infection with Neisseria meningitidis serogroup W-135 sequence type (ST)-11 in Japan. A 44-year-old woman presented with high fever, sore throat, and fatigue and was diagnosed with N. meningitidis bacteremia.

Surveillance of severe invasive group G streptococcal infections in Japan during 2002-2008.

Group G Streptococcus strains isolated from patients with severe invasive infections in the period 2002-2008 were surveyed and their prevalence compared with that observed in the period 1995-2001 in Japan. Strains with genotypes stg485, stg6792, stc36, stg6, and stg652 were isolated in both periods, whereas various new genotypes appeared in 2002-2008 and some genotypes found in 1995-2001 were not found subsequently, thus indicating a change in the prevalent genotyped strains causing severe invasive streptococcal infections.

Growth in Acanthamoeba sp. and antibiotic susceptibility of Legionella micdadei isolated from hot spring water samples.

As part of an epidemiological study on legionellosis, we attempted to isolate Legionella spp. from hot spring water samples, and were able to isolate Legionella micdadei from 3 (5.5%) of 55 samples.

Genetic features of clinical isolates of Streptococcus dysgalactiae subsp. equisimilis possessing Lancefield's group A antigen.

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, and two different emm types were observed within members of this clone.

Close correlation of streptococcal DNase B (sdaB) alleles with emm genotypes in Streptococcus pyogenes.

DNase B is a major nuclease and a possible virulence factor in Streptococcus pyogenes. The allelic diversity of streptococcal DNase B (sdaB) gene was investigated in 83 strains with 14 emm genotypes. Of the 15 alleles identified, 11 alleles carried only synonymous nucleotide substitutions.

[Drug susceptibility and analysis using pulsed-field gel electrophoresis of Streptococcus pyogenes strains isolated from the patients with streptococcal toxic shock syndrome (STSS) in Japan].

Previously, we have performed T typing of Streptococcus pyogenes strains isolated from patients with streptococcal toxic shock syndrome (STSS) in Japan, and streptococcal pyrogenic exotoxin (SPE) typing for epidemiological examination. In this study, we conducted a drug sensitivity test using these strains, and investigated the results of gene analysis by pulse-field gel electrophoresis (PFGE) of S. pyogenes strains derived from patients with STSS, the patient's family, and patients other than those with STSS.

Antimicrobial susceptibility survey of Streptococcus pyogenes isolated in Japan from patients with severe invasive group A streptococcal infections.

We assessed antimicrobial susceptibility against 211 Streptococcus pyogenes strains isolated from patients with severe invasive group A streptococcal infections. Overall, 3.8, 1.

Molecular mechanisms of high level tetracycline-resistance in group A streptococcal isolates, T serotypes 4 and 11.

The molecular mechanism of high level tetracycline resistance in T serotypes 4 and 11 group A streptococcal (GAS) isolates was examined in 61 tetracycline-resistant isolates in Japan. PCR and sequencing analyses revealed that the T serotype/emm genotype, T4/4 isolates carried tet(O) genes, which were genetically homogenous. The T11/11 and T11/89 isolates carried different subtypes of tet(M) genes, which were present on transposons Tn916 and Tn1545, respectively.