Enteropathogenic Bacteria Contamination of Unchlorinated Drinking Water in Korea, 2010

OBJECTIVES: The purpose of this study was to assess the microbiological quality of unchlorinated drinking water in Korea, 2010. One hundred and eighty unchlorinated drinking water samples were collected from various sites in Seoul and Gyeonggi province. METHODS: To investigate bacterial presence, the pour plate method was used with cultures grown on selective media for total bacteria, total coliforms, and Staphylococcus spp., respectively. RESULTS: In the 180 total bacteria investigation, 72 samples from Seoul and 33 samples from Gyeonggi province were of an unacceptable quality (>10(2) CFU/mL). Of all the samples tested, total coliforms were detected in 28 samples (15.6%) and Staphylococcus spp. in 12 samples (6.7%). Most of the coliform isolates exhibited high-level resistance to cefazolin (88.2%), cefonicid (64.7%) and ceftazidime (20.6%). In addition, Staphylococcus spp. isolates exhibited high-level resistance to mupirocin (42%). Species of Pseudomonas, Acinetobacter, Cupriavidus, Hafnia, Rahnella, Serratia, and Yersinia were isolated from the water samples. CONCLUSIONS: The results of this study suggest that consumption of unchlorinated drinking water could represent a notable risk to the health of consumers. As such, there is need for continuous monitoring of these water sources and to establish standards.

Phenotypic and genotypic characterization of Bifidobacterium isolates from healthy adult Koreans

A total of twenty-two strict anaerobic and Gram-positive Bifidobacteria, identified as B. adolescentis, B. pseudocatenulatum, or B. longum, were isolated from healthy adult Koreans. We here investigated the cell morphology, antimicrobial resistance patterns to novel antibiotics and genotypic differentiation of Bifidobacteria assessing repetitive DNA element PCR [rep-PCR] fingerprinting using the BOXA1R primer at the species level. All Bifidobacterium spp., except B. adolescentis SPM1005 and B. longum SPM1205, formed round and convex colonies. All B. adolescentis, B. pseudocatenulatum, and B. longum were opaque white glossy in colony color, and short, long, and irregular rods in morphological shape. In addition, all B. adolescentis, B. pseudocatenulatum, and B. longum formed a variety of shapes ranging from rods to Vshaped, Y-shaped, clubbed rods, or irregular. All Bifidobacterium spp., except B. adolescentis SPM0214, were sensitive to daptomycin [DAP], linezolid [LIN], and tigecycline [TIG]. B. adolescentis SPM0214 was resistant to DAP. Genomic fingerprinting patterns of B. adolescentis, B. pseudocatenulatum, and B. longum were diverse and different from those of the KCTC strain. The band size of B. adolescentis, B. pseududocatenulatum, and B. longum varied from 3.0 kb to 300 bp, 2.0 kb to 200 bp, and 2.0 kb to 500 bp, respectively. In conclusion, twenty-two strains of B. adolescentis, B. pseudocatenulatum, and B. longum isolated from healthy adult Koreans were very diverse in both phenotype and genotype. Moreover, this diversity of phenotype and genotype may support that health promoting effects of individual strain of Bifidobacterium spp. human isolates could be different and specific even within same species