Identification of an extensively drug-resistant Escherichia coli clinical strain harboring mcr-1 and bla in Korea.

The development of colistin resistance in carbapenem-resistant strains poses a serious public health problem. In this study, we collected 249 carbapenem-resistant Escherichia coli isolates from patients in Seoul in 2018, and screened all isolates for colistin resistance and for the presence of mobile colistin resistance (mcr) genes. Colistin-resistant strains were further analyzed using multilocus sequence typing, antimicrobial susceptibility testing, detection of antibiotic resistance determinants, plasmid transconjugation, and whole-genome sequencing.

Determination of 4-Methylimidazole and 2-Acetyl-4()- tetrahydroxybutylimidazole in Caramel Color and Processed Foods by LC-MS/MS.

In this study, the quick HPLC-MS/MS method for the simultaneous separation of 2-acetyl-4(5)-tetrahydrox-ybuthylimidazole (THI) and 4-(5)-methylimidazole (4-MI) in alkaline medium was used for caramel color and processed foods in Korea. After a simple sample pretreatment, 51 4-MI-labeled samples were positive for 4-MI and 2 also contained THI. The concentration of 4-MI was 260.

Total mercury, methylmercury and ethylmercury in marine fish and marine fishery products sold in Seoul, Korea.

In 2009, a survey of 177 samples of fish and fishery products from the markets in Seoul was carried out to investigate total mercury and organic mercury (methylmercury) concentrations and to establish a correlation, if any, between total and organic mercury levels. Concentrations of total and organic mercury in canned tuna ranged 0.001-2.