Viability of Clonorchis sinensis Metacercaria according to the Food-processing Methods / 감염

BACKGROUND: Endemic areas of Clonorchis sinensis are in Asia including Korea, China, Taiwan and Vietnam. Its metacercariae consumed in uncooked, or undercooked, unfrozen fish can present human a hazard. Purposes of this study are 1) to observe the effect of each food-processing method and each storage method on C. sinensis metacercariae and 2) to suggest basis to be referred as an indicator in prevention. METHODS: Live metacercariae of C. sinensis in fish collected from Nakdong River in Korea were isolated by pepsin digestion, then were injected into the center of regular-sized muscle protein (1 cm3) of flesh water fish. The sample proteins containing metacercaria were processed according to each food-processing method (heating, frying, boiling) and each storage method (chilling, freezing, pickling with vinegar, salt and soybean sauce). After these procedures, the number of dead metacercariae were counted. RESULTS: It took 10 seconds to kill all the metacercariae in muscle protein in deep frying (180 degrees C), 30 seconds in boiling (100 degrees C) and 60 seconds in dry heating. Metacercariae did not lose all the viability in 4-6 degrees C after 40 days, but lost in -10degrees C and pickling after 5 days, and in salting (salt and soybean sauce) after 3 days. CONCLUSION: These results indicated that the storing in low temperature and in such as vinegar, salt, and soybean sauce was not effective to lose the viability unless if it was kept for a long period of time. Among the food-processing methods, frying in soybean oil was the most effective method to lose the viability of metacercariae.

In vitro Effect of Sophora flavescens on the Ultrastructure of Trichomonas vaginalis Donne / 감염

BACKGROUND: Trichomonas vaginalis is a pathogenic protozoa infecting human genitourinary tract. Metronidazole is currently the drug of choice to treat T. vaginalis infection. However, because of the side effects and the occurrence of resistant strains of metronidazole, it is needed to investigate alternatives. METHODS: The antiprotozoal effect of aquatic extract from Sophora flavescens on the growth and fine structure of T. vaginalis was examined by using trypan blue exclusion assay and electron microscopy. RESULTS: One hour after the addition of 4 mg/mL extract and half hour after the addition of 5 mg/mL showed antiprotozoal effect. One to two hours after the addition of 3 mg/mL extract, the movement of flagella and axostyle had disappeared, but death of the cells had not occurred until two hours after the addition. The fine structure of the cytoplasm was also changed half an hour to two hours after addition. The number of polyribosome decreased when that of single ribosomes in the cytoplasm increased. CONCLUSION: These results indicated that S. flavescens had the antiprotozoal effect on T. vaginalis by inhibition of cell multiplication as well as an impairment of protein synthesis.

A Case of Tick Infestation in Chest Wall by Ixodes Nipponensis / 감염

We report herein an unusual case of tick bite. A 56 year old woman complained of erythematous nodular skin lesion on the left upper chest. An excision biopsy specimen of the lesion showed darkish-red nodule, in which there was a tick. It was identified as an adult female of Ixodes nipponensis by the scanning electron microscopic examination.