title: Influence of extracellular bactericidal agents on bacteria within macrophages.
abstract: We employed gentamicin-sensitive and -resistant derivatives of Escherichia coli in a macrophage phagocytosis assay that compared lambda bacteriophage and gentamicin as extracellular bactericidal agents. Colony counts and direct microscopic examination of phagocytized E. coli supported the conclusion that gentamicin entered macrophages, even at low concentrations, and contributed to their bactericidal activity. Also, two E. coli strains differing in the ability to express the adhesin of type 1 pili (FimH) were distinguishably different in intracellular survival when lambda was used as the extracellular killing agent but were indistinguishable when gentamicin was employed.
authors.affiliation: Department of Microbiology, Pathology, and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
authors.forename: Terri S
authors.initials: TS
authors.lastname: Hamrick
authors.forename: Adam H
authors.initials: AH
authors.lastname: Diaz
authors.forename: Edward A
authors.initials: EA
authors.lastname: Havell
authors.forename: John R
authors.initials: JR
authors.lastname: Horton
authors.forename: Paul E
authors.initials: PE
authors.lastname: Orndorff
mesh_terms: D018830:Adhesins, Escherichia coli / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D010582:Bacteriophage lambda / Q000472:pathogenicity*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development* / Q000821:virology; D036781:Fimbriae Proteins / Q000378:metabolism; D005839:Gentamicins / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010587:Phagocytosis
chemical_list: D018830:Adhesins, Escherichia coli; D000900:Anti-Bacterial Agents; D005839:Gentamicins; C058769:fimH protein, E coli; D036781:Fimbriae Proteins