Bacteroides fragilis is a Gram negative nonsporulating anaerobic rod bacterium that makes up about 1 to 2% of the norrnal human colonic microflora. In 1984, Myer et al. reported that some strains of B. fragilis produce enterotoxin and cause diarrheal disease in cattle and human. Since then it has been termed enterotoxigenic B. fragilis (ETBF). In this study, we tried to detect enterotoxin gene from 37 B. fragilis strains, isolated in Korean patients, to confirm the existence of ETBF and usefulness of PCR as a rapid diagnosis method. By this method, we identified 9 ETBF strains and confirmed their pathogenesis by cytotoxicity test. No significant cross- reactivity with other anaerobes or aerobes was observed. Thus, the PCR method may be considered useful for the sensitive and rapid detection of anaerobic infections. And the entire amplified PCR mixture was ligated into a pT7Blue T-vector and transformed into E. coli. When the nucleotide sequences of cloned PCR products were compared with reported enterotoxin gene, pBF529 inserted DNA sequence was nearly in good agreement with it but pBF570 inserted DNA sequence showed some difference at nucleotide 270-300. A search for nucleotide sequence homologies revealed that pBF529 exhibited 99%, but pBF570 indicated only 90% identity with reported enterotoxin gene. According to these results, it was suggested that ETBF toxin can be differentiated into at least 2 subtypes.
Animals ; Bacteroides fragilis* ; Bacteroides* ; Base Sequence ; Cattle ; Clone Cells ; Colon ; Diagnosis ; Enterotoxins* ; Humans ; Korea* ; Polymerase Chain Reaction*

PURPOSE: The purpose of our study is to provide useful information for diagnostic methods of fatty liver by childhood simple obesity and to provide correlation between serum alanine aminotransferase (ALT) for screening test and abdominal computerized tomography (CT) and liver biopsy for confirmative diagnostic methods of fatty liver. METHODS: Among 78 obese childrens who visited our hospital, CT was carried out in 26 childrens. Of these, liver biopsy was carried out in 15 childrens who had high obesity index or severe elevated ALT. Based on the level of serum ALT, 26 cases were classified into 3 groups, and compared with physical measurements and degree of fatty infiltration on CT and liver biopsy. RESULTS: 1) Correlation between ALT and physical measurements: Of 26 obese children, ALT was abnormally elevated (>30 IU/L) in 17 cases (67.4%) but there was no significant correlation between ALT and physical measurements (p>0.05). 2) Correlation between degree of fatty infiltration on CT and ALT: Of 26 cases, 13 cases (50%) revealed fatty liver on CT. The degree of fatty liver on CT had significant correlation with elevation of ALT (p<0.05). 3) Correlation between the degree of fatty infiltration on liver biopsy and ALT: Liver biopsy was performed in 15 cases of which 14 cases revealed fatty liver. But one case had normal hepatic histology with severe obesity and normal ALT. Fourteen fatty liver cases on liver biopsy were classified into 3 groups by the degree of fatty infiltration and analysed with obesity index and ALT. The histologic hepatic steatosis had no significant correlation with obesity index (p>0.05), but significant correlation with ALT (p<0.05). 4) Correlation between CT and liver biopsy finding: Both CT and liver biopsy were performed in 15 cases of which 6 cases revealed normal finding on CT and 9 cases manifested fatty liver. There was significant correlation between CT and liver biopsy findings (r=0.6094). CONCLUSION: The results of our study suggest that abdominal CT and liver biopsy are useful and accurate methods of estimating fatty liver in the childhood obesity. But biochemical abnormalities of routine liver function tests dot not correlate well with severity of the fatty liver and liver injury.
Alanine Transaminase ; Biopsy* ; Child* ; Diagnosis* ; Fatty Liver* ; Humans ; Liver Function Tests ; Liver* ; Mass Screening ; Obesity* ; Obesity, Morbid ; Pediatric Obesity ; Tomography, X-Ray Computed*