{'fraction_non_alphanumeric': 0.0384967919340055, 'fraction_numerical': 0.02474793767186068, 'mean_word_length': 4.747368421052632, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Assessment on the quality of restriction endonuclease in typing Listeria monocytogenes with pulsed-field gel electrophoreses].

OBJECTIVE
To study the relative effective factors of PFGE typing methods of Listeria monocytogenes, and set up this PFGE method of this pathogen digested with Asc I and Apa I.


METHODS
Listeria monocytogenes isolates (including 1/2a, 1/2b, 1/2c, 3a and 4b serovars) from food in China were digested with one brand of Asc I and 5 different brands of Apa I. The better test parameters were studied by the fingerprint patterns.


RESULTS
Digestion with Asc I yielded about 11 distinct fragments, and Apa I yielded similar number of fragments. However, ten percent of strains (1/2a, 1/2b serovars) showed partial digestion with all these brands of restriction endomuclease Apa I, including different enzyme concentration, different temperature and different digestion time.


CONCLUSION
AscI was suitable for digestion of all these Listeria monocytogenes isolates (1/2a, 1/2b, 1/2c, 3a and 4b serovars), but Apa I was suitable for most of the isolates (1/2a, 1/2b).