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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. The most prevalent T serotype from pharyngitis isolates was T12, followed by T1, T4, and TB3264. The most prevalent T serotype from STSS isolates was T1, followed by TB3264. Trend of increase and decrease in the frequency of T1 or TB3264 isolation from pharyngitis was correlated with that of STSS patients. The increase of T1 or TB3264 strain-infection in pharyngitis patients may increase the probability of causing STSS, indicating that careful monitoring of GAS serotypes is essential for the prediction of rapid increase of STSS in time to develop effective management strategies.

Streptococcal toxic shock syndrome (STSS) caused by Streptococcus pyogenes emm 89 strains has been increasing in several countries and reported to be linked with a recently emerged clade of emm89 strains, designated clade 3. In Japan, epidemiological and genetic information for emm89 strains remains elusive. In this study, we utilized emm89 strains isolated from both STSS (89 isolates) and non-STSS (72 isolates) infections in Japan from 2011 to 2019, and conducted whole-genome sequencing and comparative analysis, which resulted in classification of a large majority into clade 3 regardless of disease severity. In addition, STSS-associated genes and SNPs were found in clade 3 strains, including mutations of streptokinase (Ska), control of virulence sensor (CovS), serum opacity factor (SOF), sortase (SrtB), and fibronectin-binding protein F1 (PrtF1), and absence of the hylP1 gene encoding hyaluronidase. These findings provide insights into notable genetic features of emm89 strains.

In crawler-type construction machines, flexible suspension system like bogie mechanism type suspension is used to reduce and disperse the load acting on the running gear and to absorb the vibration from uneven ground. However, the quantitative effects of the bogie are not so clear. In this paper, by using a modeling and simulation method for crawler-type construction machine with bogie mechanism, which is developed by the authors, in traveling on firm grounds with continuous bumps, representative simulation cases to analyze the dynamic behavior were conducted. Then K-type and X-type bogie as flexible suspension and locked K-type and X-type bogie as rigid suspension were selected. In two bump pitch cases, effects of the bogie mechanism introduction and the bogie type on the dynamic behavior of the machine, such as the lower rollers load and the bouncing and pitching behavior were shown quantitatively and discussed.

We investigated whether CIDR-based ovulation-synchronization protocols inhibit secretion of prostaglandin (PG) F2alpha from the uterus in the following luteal phase in non-cycling beef cows. Ten early (a month) postpartum non-cycling Japanese Black beef cows were treated with (1) Ovsynch (GnRH analogue on Day 0, PGF2alpha analogue on Day 7, and GnRH analogue on Day 9; n=3), (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from Day 0; n=4), or (3) estradiol benzoate (EB) Ovsynch+CIDR (EB on Day 0 in lieu of the first GnRH treatment followed by the Ovsynch+CIDR protocol; n=3). An oxytocin challenge was administered on Day 24 to examine uterine PGF2alpha secretion. Plasma concentrations of 13,14-dihydro-15-keto- PGF2alpha were lower at 30-120 min after oxytocin administration in the Ovsynch+CIDR group and 75 min after administration in the EB Ovsynch+CIDR group than in the Ovsynch group (P