Hemin-dependent growth and hemin binding of Bartonella henselae

Bartonella henselae causes cat-scratch disease and bacillary angiomatosis p eliosis. The bacteria reside in erythrocytes of asymptomatic cats, which re present the natural reservoir for this pathogen. B, henselae is usually gro wn on blood-enriched media. Growth experiments on Brucella medium without b lood demonstrated that heme compounds are essential for the growth of B. he nselae and can completely substitute the addition of blood components. The heme precursor protoporphyrin IX alone, or in combination with FeCl2 or FeC l3, as well as transferrin or lactoferrin did not support growth, indicatin g that B. henselae cannot synthesize heme itself. Hemin supported growth ev en when free iron was chelated, indicating that hemin is also used as an ir on source. Binding assays showed that hemin starvation increased the bindin g capacity of B. henselae for hemin, providing evidence that the bacteria c arry a specific hemin uptake system, which might be regulated by hemin. (C) 2000 Federation of European Microbiological Societies. Published by Elsevi er Science B.V. All rights reserved.