Abstract |
Bovine apo- lactoferrin (apo-Lf) was added to in vitro cultures of eight strains of coliform bacteria associated with bovine mastitis. As little as 0.02 mg of APO-Lf per ml resulted in marked inhibition of growth of all coliforms. Growth inhibition was lost if saturated Lf or iron plus apo-Lf was added to the synthetic medium. The inhibition of growth increased as the concentration of apo-Lf increased from 0.02 to 0.2 mg/ml for Klebsiella pneumoniae (OARDC-A1), Klebsiella spp. (K1-21), and Aerobacter aerogenes (55-12222) and 2 mg/ml for A. aerogenes (76-2414-1), Escherichia coli (60-Lilly), E. coli (66-S16), and Klebsiella spp. (K6-24). As the concentration of apo-Lf was increased above 0.2 or 2 mg/ml, there was less inhibition of growth except for E. coli (33-C4). Apo-Lf at 20 mg/ml was bactericidal for E. coli (33-C4). Results are compatible with the hypothesis that coliform bacteria respond to low- iron environments by production of iron- sequestering agents that complete effectively with apo-Lf for free iron. Addition of apo-Lf plus citrate resulted in loss of growth inhibition. The molar ratio ( citrate to apo-Lf) was found to be more important than the absolute concentration of either component. A ratio of 75 resulted in 50% growth inhibition, whereas ratios of 300 and greater resulted in less than 10% growth inhibition. These results suggest that the ratio of citrate to Lf would be important in evaluating Lf as a nonspecific protective factor of bovine mammary secretions.
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Authors | J G Bishop, F L Schanbacher, L C Ferguson, K L Smith |
Journal | Infection and immunity
(Infect Immun)
Vol. 14
Issue 4
Pg. 911-8
(Oct 1976)
ISSN: 0019-9567 [Print] United States |
PMID | 791866
(Publication Type: Journal Article)
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Chemical References |
- Citrates
- Culture Media
- Lactoglobulins
- Iron
- Lactoferrin
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Topics |
- Animals
- Cattle
- Citrates
(pharmacology)
- Culture Media
- Dose-Response Relationship, Drug
- Enterobacter
(growth & development)
- Enterobacteriaceae
(growth & development)
- Escherichia coli
(growth & development)
- Iron
(metabolism)
- Klebsiella pneumoniae
(growth & development)
- Lactoferrin
(pharmacology)
- Lactoglobulins
(pharmacology)
- Mastitis, Bovine
(etiology)
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