Bactericidal effect of lactoferrin on Legionella pneumophila: effect of the physiological state of the organism.
Lactoferrin has been previously shown to be bactericidal for Legionella pneumophila. The current study showed that CaCl2, Mg(NO3)2, and MgCl2, but not NaCl, blocked killing. Activity was pH dependent with the greatest activity at 5.0. Sensitivity of the organism was dramatically affected by the growth conditions. Log phase 12 h, broth-grown cells were most sensitive, with older cultures becoming more resistant. Plate-grown cells were completely resistant. Lactoferrin binding, as detected by immunofluorescence microscopy, was temperature dependent (no binding at 4 degrees C), but was independent of killing.
Bortner
C A
CA
Department of Microbiology and Immunology, School of Medicine, University of Louisville, KY 40292.
Arnold
R R
RR
Miller
R D
RD
D002122:Calcium Chloride / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D007781:Lactoferrin / Q000378:metabolism / Q000494:pharmacology*; D007782:Lactoglobulins / Q000494:pharmacology*; D007875:Legionella / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride / Q000494:pharmacology; D017616:Magnesium Compounds; D008826:Microbial Sensitivity Tests; D009566:Nitrates / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature
D007782:Lactoglobulins; D017616:Magnesium Compounds; D009566:Nitrates; D015636:Magnesium Chloride; D012965:Sodium Chloride; C018330:magnesium nitrate; D007501:Iron; D007781:Lactoferrin; D008274:Magnesium; D002122:Calcium Chloride