Search

A total of 4330 food samples of which microbiological standard for Escherichia coli is negative in Korea were determined for the frequency of E. coli. Ninety six samples (2.2%) were positive for E. coli. Detection rate of E. coli varied significantly by food type and ranged from 0.3% to 10.9%. Seasoned raw meat (yukhoe) and cold bean-soup had the highest prevalence for E. coli (10.9%) followed by gimbap (5.2%), meat broth for cold noodle (2.9%) and sprout (2.1%). E. coli isolates (n=96) were investigated for their phenotypic and genotypic antimicrobial resistance patterns. Seventeen E. coli isolates (17.7%) were resistant to one or more antimicrobial agents tested. High rates of resistance to the following drugs were observed: tetracycline (15.6%), streptomycin (12.5%), ampicillin (10.4%), nalidixic acid (9.4%) and ticarcillin (9.4%). All ampicillin resistant isolates were screened for extended-spectrum β-lactamase (ESBL) production by the combination disk test. None of the E. coli isolates produced ESBLs. Seventeen out of 96 E. coli isolates which were resistant to at least one antibiotic were investigated by PCR for the presence of 3 classes of antimicrobial resistance genes (tetracycline, aminoglycosides and beta-lactams). The tetracycline resistance genes tetA and tetB were found in 7 and 5 isolates, respectively. The aminoglycoside resistance genes, strA/B, aphA1, aadA and aac(3)-IV were found in 9, 5, 2 and 2 isolates, respectively. The beta-lactam resistance gene, bla(TEM) was found in 7 isolates. Results of this study show that 13 E. coli isolates were multidrug resistant (to three or more antibiotics) and 12 isolates carried at least one antimicrobial resistance gene. These isolates can act as the reservoir for antimicrobial resistance genes and facilitate the dissemination of these genes to other pathogenic and commensal bacteria. Adequate intervention to reduce microbial contamination of these foods is strongly recommended., (Copyright © 2012 Elsevier B.V. All rights reserved.)

An epidemiologic study was performed to determine the genetic variability of rotaviruses in Seoul, South Korea. In 3,174 stool specimens from children with acute diarrhea at five referral hospitals, 571 (18%) possessed the antigen of group A rotavirus detectable by ELISA--10.8% in 2004 and 28.1% in 2005. VP7 genotyping revealed that the G3 type was found in 25.6% of all typed isolates, G4 in 23.8%, G2 in 21.6%, and G1 in 17.6%. VP4 genotyping showed that the P[8] type was detected in 66.7%, P[6] in 15.6%, P[4] in 13.0%, and P[9] in 0.2%. Because the variant P[8] type could not be amplified initially by conventional P typing primers (1T-1), PCR were performed using newly designed 1T-1S primer, which revealed that 307 specimens were the variant P[8] type. Uncommon combinations such as G4P[6] and G2P[8] were also found with relatively high prevalence, 14.6% and 12.8%, respectively. Variant P[8] types were associated with an outbreak of rotavirus in 2005.

The idea that human bocavirus (hBoV) infection possibly plays a role in gastroenteritis has been suggested because of the frequent manifestation of gastrointestinal symptoms. The purpose of this study was to investigate the prevalence of hBoV in children with gastroenteritis. We studied the etiologic agents in 962 children hospitalized with gastroenteritis. Viral etiologic agents were detected by enzyme-linked immunosorbent assay or reverse-transcriptase polymerase chain reaction. A viral agent was found in 44.4% of the study population: rotavirus, norovirus, adenovirus, and astrovirus were detected in 25.7%, 13.7%, 3.0%, and 1.1% of the study population, respectively; hBoV was detected in 0.8%, which suggests that it might play a minor role in gastroenteritis.

Three hundred forty-eight fecal specimens collected from young children with acute diarrhea in Seoul, Korea between January 1998 and February 2000 were examined for G and P types. Of these, 205 samples (59%) were confirmed as group A rotavirus by ELISA for the detection of VP6 antigen. Confirmed rotavirus isolates were characterized using G serotyping ELISA and RT-PCR methodologies for G and P genotyping of the outer capsid proteins VP7 and VP4, respectively. Serotyping of the outer capsid protein, VP7, revealed G4 as the dominant circulating serotype (41%) followed by G1 (28%) and quite a high incidence of mixed infection (14%). Genotyping of the VP4 protein was carried out on 55 of the rotavirus isolates with the dominant type being P[8] (46%). Of interest were a number of unusual G and P type combinations detected in Korea for the first time, especially the P[4] genotype associated with non-G2 serotypes. There were also a number of P[6] isolates identified including one G2P[6] isolate., (Copyright 2003 Wiley-Liss, Inc.)