Search

Introduction: Haemophilus influenzae with a reduced susceptibility to quinolones (quinolone low-susceptible H. influenzae) has recently emerged in Japan. In addition, the regional outbreak of the quinolone low-susceptible H. influenzae ST422 clone has been reported. In this study, we isolated this clone from an acute care hospital located in a geographically different area from the previous outbreak and characterised the nature of this clone., Methods: Eighty-nine H. influenzae isolated between 2017 and 2019 were tested. The antimicrobial susceptibility was determined by the broth dilution method. The genetic background was analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Growth ability and β-lactamase acquisition were evaluated by growth curve analysis and conjugative transfer experiments, respectively., Results: Quinolone low-susceptible isolates accounted for 4.2% (1/24) in 2018 and 13.9% (5/36) in 2019. Most of the quinolone low-susceptible strains (83.3%) were classified as ST422 and had amino acid substitutions in quinolone resistance-determining regions in both GyrA and ParC. The patients' backgrounds were highly diverse. In addition, these isolates showed the same PFGE pattern as outbreak strains. The growth of ST422 clone was relatively faster than other clones. Furthermore, ST422 clone was able to acquire β-lactamase from a β-lactamase positive strain by horizontal transfer, becoming highly resistant to β-lactams., Conclusion: Our study indicated that the quinolone low-susceptible H. influenzae ST422 clone has been spreading in the community undetected. In addition, this clone has the potential to grow faster and become more resistant through exogenous gene transfer. Therefore, ST422 clone should be monitored attention throughout Japan., (Copyright © 2021 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objectives: To examine whether a seasonal fluctuation exists with rheumatoid arthritis (RA) activity and to analyse seasonal effects of varying components that express disease activity in RA patients., Methods: A group of 1665 RA patients (mean age 57.2 yrs, mean disease duration 9.9 yrs) whose data were available for 10 consecutive phases from a large observational cohort study conducted at our institution from October 2000 to April 2005, bi-annually, were evaluated. Ten criteria were analysed to assess RA disease activity., Results: All criteria revealed decrease in disease activity during fall and increase in disease activity during spring, except for the physician's global assessment of disease activity in which significant differences were not observed between the two seasons., Conclusions: We found definite seasonal differences in RA patients, both subjectively and objectively. RA disease activity was higher in spring and lower during fall. Seasonal changes may play an important role in evaluating disease activity of RA patients and should be taken into account when examining these patients.

Prospective studies of posttransfusion hepatitis carried out in the past decade showed that 18.1% of the blood transfusions resulted in non-A non-B hepatitis in Japan. As an approach to the prevention of posttransfusion non-A non-B hepatitis (PTNANB), anti-hepatitis C virus (HCV) positivity was measured in 2,970 blood donations in the Tokyo area, and in 200 children aged between 6 and 15 years. Thirty-four cases were anti-HCV-positive, showing an overall positivity of 1.14%. None of the 200 children younger than 15 years old were positive. Correlation of anti-HCV positivity with the serum ALT levels was observed, but by reducing the accepted ALT levels from 35 Karmen Units (KU) down to 25 KU, it is estimated that 62.5% of the observed PTNANB would still have occurred, and 5.1% of the donated blood could not be used for transfusion. On the other hand, it is estimated that the majority of PTNANB could be prevented, with the loss of 1.14% of donated blood units, using the anti-HCV screening test.