title: [The in vitro killing of intracellular Mycobacterium smegmatis by Mycobacteriophage].
abstract: OBJECTIVE
  To study the effect of Mycobacteriophage on the lysis of intracellular Mycobacterium smegmatis.
  
  
  METHODS
  Peritoneal macrophages from BALB/C mice were incubated with Mycobacterium smegmatis for 4 h, and the extracellular bacteria were removed. Then the infected macrophages were treated for 2 h with normal saline, or different doses of Mycobacteriophages (2.1 x 10(7) PFU, 2.1 x 10(6) PFU, and 2.1 x 10(5) PFU, respectively), all in a volume of 0.1 ml, and then the extracellular phages and Mycobacterium smegmatis were removed by washing. After incubation for 24 h, the number of viable intracellular bacteria was determined. The intracellular changes after infection of host bacteria by bacteriophages in the macrophages were observed by electron microscopy.
  
  
  RESULTS
  The logarithm 10 of viable intracellular bacteria unit was 5.74 +/- 0.18 in the saline group, 4.77 +/- 0.08 in the high dose phage group (P < 0.01), 4.97 +/- 0.17 in the moderate dose phage group (P < 0.01), and 5.33 +/- 0.13 in the low dose phage group (P > 0.05). Electron microscopy confirmed the infection of intracellular bacteria by the bacteriophages and the production of filial bacteriophages.
  
  
  CONCLUSIONS
  Mycobacteriophages phagocytosed by macrophages are capable of killing the infected mycobacteria. The result suggests that the use of Mycobacteriophages is a potentially novel strategy in the treatment of intracellular bacterial infection.
authors.affiliation: Department of Pulmonary Disease, First Affiliated Hospital of Chongqing University of Medical Sciences, Chongqing 400016, China.
authors.forename: Li
authors.initials: L
authors.lastname: Peng
authors.forename: Bao-wen
authors.initials: BW
authors.lastname: Chen
authors.forename: Yong-ai
authors.initials: YA
authors.lastname: Luo
authors.forename: Xiao-bing
authors.initials: XB
authors.lastname: Shen
authors.forename: You-lun
authors.initials: YL
authors.lastname: Li
authors.forename: Guo-zhi
authors.initials: GZ
authors.lastname: Wang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D017737:Macrophages, Peritoneal / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009160:Mycobacteriophages; D020102:Mycobacterium smegmatis / Q000821:virology*; D010587:Phagocytosis