Antiviral effect of cationic compounds on bacteriophages

Abstract

The antiviral activity of several cationic compounds – cetyltrimethylammonium bromide (CTAB), chitosan, nisin, and lysozyme – was investigated on the bacteriophage c2 (DNA head and non-contractile tail) infecting Lactococcus strains and the bacteriophage MS2 (F-specific RNA) infecting E. coli. Firstly, these activities were evaluated in a phosphate buffer pH 7 – 10 mM. The CTAB had a virucidal effect on the Lactococcus bacteriophages, but not on the MS2. After 1 min of contact with 0.125 mM CTAB, the c2 population was reduced from 6 to 1.5 log(pfu)/mL and completely deactivated at 1 mM. On the contrary, chitosan inhibited the MS2 more than it did the bacteriophages c2. No antiviral effect was observed for the nisin or the lysozyme on bacteriophages after 1 min of treatment. A 1 and 2.5 log reduction was respectively observed for nisin and lysozyme when the treatment time increased (5 or 10 min). These results showed that the antiviral effect depended both on the virus and structure of the antimicrobial compounds. The antiviral activity of these compounds was also evaluated in different physico-chemical conditions and in complex matrices. The antiviral activity of CTAB was impaired in acid pH and with an increase of the ionic strength. These results might be explained by the electrostatic interactions between cationic compounds and negatively charged particles such as bacteriophages or other compounds in a matrix. Milk proved to be protective suggesting the components of food could interfere with antimicrobial compounds.

Virucidal Influence of Ionic Liquids on Phages P100 and MS2

“…In another study the effect of CTAB (cetyltrimethylammoninium bromide) was tested on phages c2 and MS2. In keeping with the results of our study, here RNA phage MS2 infectivity was not reduced while infectivity of the DNA phage c2 was reduced (Chatain-Ly et al, 2013 ).…”

Role of bacteriophages in STEC infections: new implications for the design of prophylactic and treatment approaches

“…This positively charged polymeric polysaccharide has been reported to inhibit other bacteriophages and probably acts through electrostatic interactions with negatively charged capsid proteins 5 . Based on these effects we propose that chitosan may be a viable alternative for the treatment of STEC infections.…”

“…Chitosan, a linear polysaccharide polymer obtained after the deacetylation of chitin, the structural element in the exoskeleton of crustaceans, possesses strong antimicrobial activity against several pathogenic microorganisms 4 . Its antiviral activity was reported on the bacteriophage c2, which infects Lactococcus strains, and on bacteriophage MS2, which infects E. coli 5 without affecting significantly the growth of the bacterial culture 6 . In order to test our hypothesis, which would make Stx-encoding bacteriophages a new target for preventing and treating STEC infections, we used chitosan as an anti-bacteriophage agent in vitro and in vivo .…”

Role of bacteriophages in STEC infections: new implications for the design of prophylactic and treatment approaches

“…Our findings indicate that chitosan possesses strong anti-bacteriophage effects in vitro and probably also in vivo, as demonstrated with the lysogenic E. coli C600ΔTOX:GFP strain. This positively charged polymeric polysaccharide has been reported to inhibit other bacteriophages and probably acts through electrostatic interactions with negatively charged capsid proteins 6 . Based on these effects we propose that chitosan could be a viable alternative for the treatment of STEC infections.…”

“…Chitosan, a linear polysaccharide polymer obtained after the deacetylation of chitin, the structural element in the exoskeleton of crustaceans, possesses strong antimicrobial activity against several pathogenic microorganisms 5 . Its antiviral activity was reported on the bacteriophage c2, which infects Lactococcus strains, and on bacteriophage MS2, which infects E. coli 6 , without significantly affecting the growth of the bacterial strains 7 . In order to test our hypothesis, which would make Stx-encoding bacteriophages a new target for prevention and treatment of STEC infections; we used chitosan as an anti-bacteriophage agent both in vitro and in vivo .…”