Background The frequency of antimicrobial resistance has steadily increased worldwide, induced by inappropriate use of antibiotics in a variety of settings. We analyzed the ecological correlation between fluoroquinolone consumption and levofloxacin resistance in Escherichia coli in Japan. Methods We collected information on cases of E. coli resistant to levofloxacin in 2015–2016 in all 47 prefectures from the Japan Nosocomial Infections Surveillance system. Information on fluoroquinolone consumption was obtained from pharmaceutical sales data. To address potential confounding, we also collected information on the number of physicians, nurses, and medical facilities per 100,000 individuals. Results We identified higher fluoroquinolone consumption and higher resistance in western prefectures, and lower consumption and resistance in eastern prefectures. Multivariate analysis identified a positive correlation between fluoroquinolone consumption and levofloxacin resistance in both 2015 and 2016. Conclusions Fluoroquinolone consumption and levofloxacin-resistant E. coli are potentially associated on a nationwide scale. The relationship between the two must be elucidated using additional studies with different epidemiological designs, so that any possible counter-measures, including alternative prescription, can be considered in the future.

Objective This study focused on carbapenem resistance in Pseudomonas aeruginosa and examined potential ecological correlations with carbapenem use in Japan. Methods The proportion of carbapenem-resistant P. aeruginosa isolates from 2015 and 2016 by prefecture was obtained from the Japan Nosocomial Infections Surveillance system. Data on carbapenem use was obtained from the National Database of Health Insurance Claims. The correlation between the proportion of carbapenem-resistant isolates and carbapenem consumption was assessed in a cross-sectional manner. The study also collected information on other variables including the numbers of physicians, nurses and medical facilities per 100 000 individuals by prefecture. Results Both the proportion of carbapenem-resistant P. aeruginosa isolates and levels of carbapenem use were higher in western Japan. Using a multivariate model, only carbapenem use remained significantly associated with the proportion of carbapenem-resistant isolates. Conclusions Carbapenem use and the proportion of carbapenem-resistant P. aeruginosa isolates were positively correlated. By longitudinal data collection, this approach offers an avenue to establish causal links as the frequency of carbapenem-resistant P. aeruginosa isolates starts to change in the future.

No abstract

This study investigated the efficacy of ceftriaxone (CTRX) for the treatment of aspiration pneumonia. We compared patients treated with CTRX versus sulbactam/ampicillin (SBT/ABPC). One-to-one propensity score matching was performed to compare the success rates of antibiotic therapy and in-hospital mortality between the groups. Moreover, the duration of antibiotic use, hospital period, and total antibiotic costs were compared among effective patients in the groups. There were 43 and 20 patients in the SBT/ABPC and CTRX groups, respectively. The propensity score matching included 20 patients in each group. There was no significant difference in the success rate of antibiotic therapy (85％ vs 95％, P = 0.62) or in-hospital mortality (25％ vs 5.0％, P = 0.22) between the groups. In addition, there was no significant difference in the duration of antibiotic use (median: 9 days vs 10 days, P = 0.94) or hospitalization period (median: 19 days vs 18 days, P = 0.94) among the effective patients in the groups. However, the total antibiotic costs were significantly lower in the CTRX effective group than the SBT/ABPC effective group (13,731 ± 4,903 yen vs 20.772 ± 6,840 yen, P = 0.001). CTRX may be another choice for antibiotic treatment for patients with aspiration pneumonia when they have no risk of drug-resistant bacteria.