ISOLATION OF STAPHYLOCOCCUS-AUREUS L FORMS FROM EXPERIMENTALLY INDUCED BOVINE MASTITIS
ISOLATION OF STAPHYLOCOCCUS-AUREUS L FORMS FROM EXPERIMENTALLY INDUCED BOVINE MASTITIS
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DOI：
10.1128/jcm.25.10.1956-1961.1987
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发表时间：
1987-10-01
影响因子：
9.4
通讯作者：
OWENS, WE
中科院分区：
文献类型：
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作者：
OWENS, WE
从实验感染金黄色葡萄球菌的奶牛乳样品中分离细菌L型。最初，从44个S中的12个体外诱导细菌L型。金黄色葡萄球菌菌株分离的牛乳房炎。在两个实验中，用体外显示容易诱导为L型的菌株和S。305.第三百零五章每个乳区的乳腺感染103或106 CFU的试验菌株。在出现临床乳腺炎的第一个体征时，开始每乳区100，000 U青霉素G治疗。每天收集乳汁样品，并在牛血琼脂和PPLO琼脂（Difco Laboratories，Detroit，Mich.）10%马血清和5%氯化钠在抗生素治疗后，从两个实验中从感染腺体收集的乳汁样品中分离葡萄球菌L型。具有最高浓度的白细胞和细菌的腺体最有可能在治疗开始后在乳汁样品中产生L型。携带L型的奶牛通常在停止抗生素治疗后产生亲本微生物。没有检测到的变化发生在抗生素的亲和力，凝固酶的生产，或生化活性的菌株诱导到L型，然后恢复到亲本形式。这些结果表明，L型可以发生在治疗牛乳房炎和L型可能是一个解释的葡萄球菌性牛乳房炎抗生素治疗反应差。
Bacterial L forms were isolated from milk samples of dairy cattle infected experimentally with Staphylococcus aureus. Initially, bacterial L forms were induced in vitro from 12 of 44 S. aureus strains isolated from bovine mastitis. Cows were experimentally infected in two experiments with strains shown in vitro to be easily inducible to L form and with S. aureus Newbould 305. Each quarter of the mammary gland was infected with either 103 or 106 CFU of the test strains. Treatment was initiated with 100,000 U of penicillin G per quarter at the first signs of clinical mastitis. Milk samples were collected daily and cultured on bovine blood agar and PPLO agar (Difco Laboratories, Detroit, Mich.) with 10% horse serum and 5% NaCl. Staphylococcal L forms were isolated from milk samples collected from infected glands in both experiments after antibiotic therapy. Glands with the highest concentrations of leukocytes and bacteria were most likely to yield L forms in milk samples after treatment was initiated. Cows harboring L forms typically yielded parental organisms after cessation of antibiotic therapy. No detectable changes occurred in antibiotic susceptibilities, coagulase production, or biochemical activities in strains induced to L form followed by reversion to the parental form. These results demonstrated that L forms can occur during treatment of bovine mastitis and that L forms may be one explanation for the poor response of staphylococcal bovine mastitis to antibiotic therapy.