Phagocytosis of microbial L-forms

Little data are available regarding L-form phagocyte interactions. Due to difficulty with more conventional methods, a serum-free technique of surface phagocytosis employing cellulose ester micropore filters, fluorochrome staining, and reflecting fluorescence microscopy was developed. Intracellular localization of L-frms was confirmed by electron microscopy. In timed experiments, phagocytosis of a group D Streptococcus (ATCC 23241) and its L-form (T53I) were maximal at 30 min, although the bacteria were consistently better phagocyted. Phagocytosis of an Escherichia coli (strain Yale) and its L-form was also demonstrated with the same technique. The lesser phagocytosis of L-forms may be related to their lower chemotactic activity.