{'fraction_non_alphanumeric': 0.03404669260700389, 'fraction_numerical': 0.04377431906614786, 'mean_word_length': 5.351851851851852, '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}}
Comparison of the virulence of O:9,12 and O:4,5,12 Salmonella typhimurium his+ transductants for mice

The purpose of these experiments was to determine whether qualitative differences in the O repeat unit of the lipopolysaccharide of pathogenic Salmonella species affected virulence for mice. O:4,5,12 and O:9,12 sister his+ transductants were derived from a virulent Salmonella typhimurium. Fermentation markers were introduced by transduction to differentiate these strains, and the strains were used as mixed challenge to CF1 and C57B1/6J mice. Liver and spleen cultures of the mice of various intervals after challenge indicated that the O:4,5,12 member of the nearly isogenic pair regularly multiplied to a greater extent than the O:9,12 after intraperitoneal challenge for both strains of mice. After oral challenge, there was little difference in the amount of multiplication of the O:4,5,12 and O:9,12 strains in CF1 mice, but the O:4,5,12 was the predominant strain recovered in 8 of 10 instances in the C57B1/6J mice.