CHEMICAL INTERFERENCE WITH PHAGE GROWTH 269 



Chemical agents whose inactivating action may be reversed by 

 simple procedures such as dilution, heating, or prolonged storage 

 apparently act by preventing adsorption. This may well be due 

 to a reversible interaction with groupings which are essential for 

 attachment. An inhibitor of this nature may be found in fresh 

 lysates of T2 coliphage (Sagik, 1954). The presence of such a 

 substance in a lysate containing bacterial products is not too 

 surprising since the same type of transient, reversible inactivation 

 of phage can be obtained with simple aldehydes and aldoses 

 (Kligler and Olenick, 1 943) and with a phospholipid (Levin and 

 Lominski, 1936). 



Not only is it possible to damage the attachment organ of the 

 phage but it is also possible to destroy the complementary recep- 

 tor sites on the surface of the bacteria. Chemical agents that 

 can do this are described in Chapter X. 



Chapter X presents an account of the inorganic requirements 

 for adsorption. It is possible to prevent adsorption by creating a 

 deficiency of cations, such as the removal of calcium ions by 

 citrate, or by adding a nonfunctional cation which may compete 

 with functional ones. Garen and Puck (1951) showed that the 

 second step of adsorption can be prevented by zinc ions in infec- 

 tions with Tl but not with T2. This was due to a specific 

 competition with calcium or inagnesium ions which are required 

 by Tl. Reversible attachment was not aflfected by zinc. In 

 effect, this represents a type of "cure" in that the infectious 

 agent, though adsorbed, is unable to establish infection and can 

 be removed with the restoration of a viable host. Another case 

 with similar consequences is found in the action of apple pectin 

 on T2 (Reiter, 1956). Reiter presented convincing evidence 

 that the inhibitory action of pectin on the production of T2 

 phage is primarily due to a prevention of the irreversible step of 

 adsorption. The phage which had been adsorbed in the 

 presence of pectin was not inactivated, had not penetrated, and 

 could be recovered in an active form by elution, or by artificial 

 lysis of the bacteria. Since excess NaCl reversed the inhibition, 

 pectin was considered to act as a polyelectrolyte which can 



