{'fraction_non_alphanumeric': 0.02103049421661409, 'fraction_numerical': 0.0, 'mean_word_length': 5.141935483870967, '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}}
Experimental staphylococcal mastitis in the mouse: effects of extracellular products and whole bacterial cells from a high-virulence and a low-virulence strain of Staphylococcus aureus.

SUMMARY Cell-free preparations of “toxin” were made from two strains of Staphy-lococcus aureus, one known to be of high virulence and the other of low virulence in the mammary gland of cattle. These preparations were similar in their in-vitro properties and in their clinical and histopathological effect when inoculated into the mammary gland of mice. However, when live staphylococci were inoculated into the mammary gland of mice a difference in virulence corresponding to that seen in cattle was detected by the clinical response, and by the histopathological appearance, the number of organisms, and the amount of α-lysin present in the infected glands. The reasons for the failure of the low-virulence strain to express its potential virulence are discussed.