Bacteriophage therapy of Salmonella enterica: a fresh appraisal of bacteriophage therapy.
BACKGROUND
The most serious criticisms leveled at bacteriophage therapy are as follows: phages induce neutralizing antibodies, phages are active only when administered shortly after bacterial infection, and phage-resistant bacteria emerge rapidly in the course of therapy.


METHODS
Phages lytic for several Salmonella enterica serovars were isolated by means of standard protocols from feces of patients with gastroenteritis. Growth of S. enterica serovar Paratyphi B (Salp572(phi1S)) in the presence of phage phi1 (selected from among 8 phages for its larger host range) provided a phage phi1-resistant bacterial strain (Salp572(phi1R)). The properties of the Salp572(phi1S) and Salp572(phi1R) strains and of phage phi1 were studied in a mouse model of experimental infection.


RESULTS
Phages induced nonneutralizing antibodies and were active 2 weeks after experimental infection of mice; phage-resistant bacteria were avirulent and short lived in vivo. More importantly, phage-resistant bacteria were excellent vaccines, protecting against lethal doses of heterologous S. enterica serovars.


CONCLUSIONS
Phage therapy effectiveness has not yet been properly assessed.
Capparelli
Rosanna
R
Faculty of Biotechnology, University of Naples Federico II, Naples, Italy.
Nocerino
Nunzia
N
Iannaccone
Marco
M
Ercolini
Danilo
D
Parlato
Marianna
M
Chiara
Medaglia
M
Iannelli
Domenico
D
D000818:Animals; D000918:Antibody Specificity; D001435:Bacteriophages / Q000276:immunology / Q000302:isolation & purification*; D004195:Disease Models, Animal; D005260:Female; D005759:Gastroenteritis / Q000382:microbiology* / Q000628:therapy*; D051379:Mice; D019936:Probiotics / Q000627:therapeutic use*; D012484:Salmonella paratyphi B; D014169:Transformation, Bacterial