Systematic Review of Heavy Metal Concentrations in Fish and Shellfish in Korea / 이화의대지

OBJECTIVES: Heavy metals ingested through the consumption of aquatic products can accumulate in the human body over the long-term and cause various health problems. This study aims to present comprehensive data on the amount of heavy metals found in fish and shellfish in Korea using a systematic review of studies that report on that issue. METHODS: The study used the following databases: PubMed, Korean Studies Information Service System, and Research Information Sharing Service. The search terms for PubMed included fish OR shellfish OR seafood AND mercury OR cadmium OR lead OR heavy metal AND Korea. The search terms for Korean Studies Information Service System and Research Information Sharing Service included eoryu sueun, eoryu kadeumyum, eoryu nab, eoryu jung-geumsog, paeryu sueun, paeryu kadeumyum, paeryu nab, paeryu jung-geumsog, eopaeryu sueun, eopaeryu kadeumyum, eopaeryu nab, and eopaeryu jung-geumsog. RESULTS: A total of 32 articles were selected for review. The total mercury, lead, and cadmium concentrations in fish and shellfish reported in each of the articles are summarized, as are the species of fish and shellfish with relatively high concentrations of heavy metals. Total mercury concentrations tended to be higher in predatory fish species, such as sharks, billfishes, and tuna, while lead and cadmium concentrations tended to be higher in shellfish. CONCLUSION: This paper is the first to report a comprehensive summary of the concentrations of heavy metals in fish and shellfish. This data could be used as evidence to protect Koreans from exposure to heavy metals due to the consumption of highly polluted aquatic products.

Molecular Epidemiology of Clostridium perfringens Isolated from Food Poisoning in Seoul, 2013

Clostridium perfringens food poisoning ranks among the most common gastrointestinal diseases in developed countries. In Korea, C. perfringens food poisoning gradually increases. Using PCR, 72 strains of C. perfringens isolated in Seoul, 2013 were tested for the presence of toxin genes. Of the tested strains, 32 isolates carried the cpe gene, 37 isolates carried the cpb2 gene and 3 isolates carried the cpe and cpb2 genes, respectively. 32 cpe-positive strains were isolated from the food poisoning patient, whereas among 37 cpb2-positive strains, 22 strains were isolated from asymptomatic person. To investigate epidemiological relationship between the isolates, Pulsed-filed gel electrophoresis (PFGE) was performed. The genetic relatedness of the isolates ranged from 55.9% to 100% and 47 distinct PFGE profiles were observed. The results show that the cpe-positive outbreak strains showed close genetic relation, whereas the cpb2-positive isolates revealed a wide genetic diversity.

Infection Frequency and Mixed infection on Eight Viruses from Patients with Acute Respiratory Syndromes in Seoul

For our survey of the infection frequency and mixed infection of the viruses causing acute respiratory syndromes, we analyzed those viruses from acute respiratory patients in Seoul. Total 1,038 specimens of oropharyngeal swab were tested by the real-time polymerase chain reaction (PCR) kit (Kogenebiotech, Korea) from Jan. to Dec. in 2013. Virus detection rate causing acute respiratory infection was 46% (476/1,038). The most frequently isolated virus was only hRV (21.6%, 103/476), followed by only ADV (8.96%, 93/476), only IFV A (H3N2) (18.1%, 86/476), and only hCoV (7.8%, 37/476) etc. Most of acute respiratory viruses had severe fever. Infection frequency information and mixed infection status on respiratory viruses circulating in Seoul will be helpful for the management of acute respiratory infection and for epidemiological continuous studies.

Epidemiological Relationship of Enterotoxigenic Escherichia coli and Enteroaggregative E. coli Isolated from Patients with Diarrhea in Seoul

Of total 1,438 specimens of patients with diarrhea in Seoul, 2011, 217 samples (15%) were found pathogenic Escherichia coli that included 192 strains (89%) of enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC). The highest isolation rate for ETEC and EAEC was found in August and September. Sixty two pathogenic E. coli strains (34 ETEC and 28 EAEC strains) were selected from 175 strains (94 ETEC and 81 EAEC strains) isolated in August and September. Of 94 strains characterized for ETEC phenotype, 76 (81%) expressed heat-stable toxin (ST) only. Antimicrobial susceptibility test was carried out by using sixteen types of antibiotics. A high level of antimicrobial resistance to tetracycline (57%), ampicillin and ticarcillin (54%) was observed among EAEC isolates while the highest resistance rate of ETEC was found for nalidixic acid (47%), followed by tetracycline (32%). As to the antimicrobial susceptibility test, EAEC showed the complicated multi-drug resistant patterns in which the resistance was higher than ETEC. Pulsed-field gel electrophoresis (PFGE) was carried out to examine the genetic relatedness among ETEC and EAEC isolates. Except for 11 strains, 51 strains were divided by eight pulsotypes. In PFGE analysis, isolates from foodborne disease outbreaks in August and September 2011 showed close relation.