Public Health Institutes
In total, 41.1% of the 1,185 human-derived strains and 89.7% of the 351 food-derived strains indicated resistance to one or more antimicrobials. Although this investigation was not conducted as a routine national surveillance operation, the results here are considered to reflect the current status in Japan, given that the investigation covered all regions of Japan and the proportion of resistant strains isolated between 2015 and 2017 was similar. Table appears to show that resistance to cephalosporins (CTX, CAZ, CFX) rose in strains isolated in 2017, but the figures were the same as 2015 and 2016 or even lower when the focus was limited to domestic chicken meat (figures in parentheses). This suggested that the strains isolated in 2017 contained a high proportion of strains from foreign chicken meat. As for multidrug resistance, the proportion of three-drug resistance was large both among human-derived strains and among food-derived strains. Twenty-one among human-derived strains, and 30 among food-derived strains, indicated advanced resistance to as many as six to ten drugs.