ABSTRACT
The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is increasing globally. However, a few studies have addressed their epidemiology in Seoul, Korea. In this study, we conducted one-year surveillance of CRE among 1,468 clinical isolates of Enterobacteriaceae at the hospital in Seoul with molecular characterization of carbapenemase genes. About 85% of CRE-positive samples were isolated from the elderly age group (above 60 years). The most common isolated organisms were Klebsiella pneumoniae (K. pneumoniae) (56.5%) and Escherichia coli (E.coli) (17.0%). We detected six different Carbapenemase-producing Enterobacteriaceae (CPE) of blaKPC, blaNDM, blaOXA, blaVIM, blaIMP, and blaGES alone or in combination with other bla genes. Typically, 853 (58.1%) isolates were tested positive for at least one CPE. KPC (K. pneumoniae carbapenemase)-2 was the most common CPE type (46.0%) followed by NDM (New Delhi metallo-β-lactamase)-1 (5.9%). KPC-2 was most commonly found in K. pneumoniae (494/676 isolates [73.1%]) and E.coli (107/676 isolates [15.8%]), whereas NDM-1 was commonly found in Enterobacter cloacae complex (20/86 isolates [23.3%]). Detailed information and molecular characteristics of CPE is essential to prevent the spread of these pathogens.
ABSTRACT
Legionella species are abundant in the built environment and are increasingly recognized as a cause of Legionnaires' disease (LD). As the number of cases of Legionnaires' disease acquired by local communities in the Seoul metropolitan area in Korea has been increased, there was concern that changes in environmental factors could affect disease outbreaks. We described the association between climatic variables and occurrence of legionellosis in Korea and Legionella detection rate in Seoul area. A total of 418 cases of legionellosis were reported between 2014 and 2017. There was a seasonal peak in summer. LD continuously occurred from early spring to winter every year and rapidly increased in summer. In the regression analysis, the primary variables of interest- PM2.5 (µg/m³), NO₂ (ppb), and a number of the date of issue O₃ warning were not significant except for average temperature (R²=0.8075). The Legionella detection rate in Seoul, Korea showed a trend similar to precipitation (P=0.708, ANOVA). A relatively high proportion of Legionella detection rate was shown, especially cooling tower (17.7%) and public bath (19.3%). This finding is in line with current understanding of the ecological profile of this pathogen and supports the assertion that legionellosis occurs through contamination of water sources.
Subject(s)
Baths , Disease Outbreaks , Epidemiology , Korea , Legionella , Legionellosis , Legionnaires' Disease , Regression Analysis , Seasons , Seoul , WaterABSTRACT
Diarrheagenic Escherichia coli (E. coli) is a main cause of diarrhea worldwide. This study reports the investigation on the occurrence of enterotoxigenic E. coli (ETEC) serotype O27:H7-associated foodborne gastrointestinal disease that occurred at two schools, one middle school and one high school, in Seoul, Korea in June 2015. The immediate government investigation in 1,216 students and 19 food handlers in these two schools revealed that 116 students, 32 students in the middle school and 84 students in the high school, and 2 food handlers, one from middle school and the other from high school, developed gastrointestinal illness symptoms including diarrhea. Following lab investigation identified 29 ETEC serotype O27:H7 strains, 27 from 116 students and 2 from 19 food handlers. Pattern of pulsed-field gel electrophoresis analysis of ETEC isolates suggested that ETEC serotype O27:H7 caused the diarrheal outbreak in June 2015 in Seoul, Korea was a specific clone. In addition, these ETEC serotype O27:H7 isolates were highly resistance to the several antibiotics. The results from the present study provide the evidence that ETEC serotype O27:H7 can be an important cause of domestic foodborne outbreak in Korea.