The acquisition of human lactoferrin by Mycoplasma pneumoniae

We tested the in vitro binding of human iron-sequestering lactoferrin and transferrin by the mucosal-surface pathogens, Mycoplasma pneumoniae and Mycoplasma genitalium. Mycoplasma pneumoniae bound lactoferrin, but not transferrin, in a saturable and specific manner. Analysis of binding data indicates less than 10,000 lactoferrin receptors per micro-organism with a moderately high binding affinity of 20 nM. No significant binding of lactoferrin or transferrin by M. genitalium was observed.