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Increased fragility of Escherichia coli after infection with bacteriophage M13
Abstract:
Male strains of Escherichia coli infected with filamentous phage M13 released the progeny phage particles from intact cells. At the same time, the cells continued to grow and multiply at a slightly lower rate than the uninfected cells. Concomitant with the phage release, lipopolysaccharide from the cell wall of the infected cells was also released. The buoyant density of E. coli HfrC in diaginol, 1.25 g/cc, did not change as a result of infection. Detergents like sodium dodecyl sulfate and Sarkosyl specifically lysed the infected cells. The infected cells showed enhanced fragility as indicated by inactivation by various stresses, namely heat, osmotic shock, and freezing and thawing. It is concluded that the infection with M13 causes certain alterations in the surface structure of E. coli, thus making the cells more fragile.
Insights
Male Escherichia coli (E. coli) infected with M13 phage release progeny and lipopolysaccharide from intact cells. This infection increases cell fragility, indicating alterations in the E. coli surface structure.
Area of Science:
- Microbiology
- Molecular Biology
- Virology
Background:
- Filamentous phage M13 infects male Escherichia coli strains.
- Bacterial cell wall composition and integrity are crucial for survival.
Purpose of the Study:
- To investigate the effects of M13 phage infection on E. coli cell properties.
- To determine if M13 infection alters E. coli cell surface structure and fragility.
Main Methods:
- Infection of male E. coli HfrC with M13 phage.
- Monitoring of phage and lipopolysaccharide release.
- Assessment of cell density and lysis susceptibility to detergents (sodium dodecyl sulfate, Sarkosyl).
- Evaluation of cell fragility under various stress conditions (heat, osmotic shock, freezing/thawing).
Main Results:
- Infected E. coli released M13 phage and lipopolysaccharide from intact cells.
- Infected cells exhibited slightly reduced growth and multiplication rates.
- Buoyant density of infected E. coli HfrC remained unchanged.
- Infected cells were specifically lysed by detergents and showed increased fragility to heat, osmotic shock, and freeze-thaw cycles.
Conclusions:
- M13 phage infection induces alterations in the E. coli cell surface structure.
- These surface alterations lead to increased cell fragility and susceptibility to lysis.