Double sugar-tyrosine medium improves O-1 phage Salmonella screening.
A modification of the procedure for O-1 phage Salmonella screening is presented. The novel method is based on the use of two media, i.e., a new medium (double sugar-tyrosine [DST]), which permits the combination of adonitol and sucrose fermentation and tyrosine clearing tests, and the previously described o-nitrophenyl-beta-D-galactopyranoside urease indole medium. In comparative trials, the new procedure and the conventional one were used to screen for Salmonella isolates from 553 lactose-negative strains of members of the family Enterobacteriaceae. The O-1 phage test, performed on DST medium, recognized the same number of phage-susceptible Salmonella strains as did the standardized method; however, it permitted the correct identification of a greater number of phage-resistant strains for discard (95.6 versus 85.3%). In particular, DST medium presented a higher efficacy than triple sugar iron agar (which is the corresponding medium in the reference procedure) in correctly identifying phage-negative cultures for discard (69.1 versus 28.5%).
Thaller
M C
MC
Istituto di Microbiologia, Università, La Sapienza, Rome, Italy.
Dainelli
B
B
Berlutti
F
F
Schippa
S
S
Fontana
C
C
Pezzi
R
R
D003470:Culture Media; D005069:Evaluation Studies as Topic; D006801:Humans; D008828:Microbiological Techniques; D012475:Salmonella / Q000145:classification / Q000302:isolation & purification*; D012483:Salmonella Phages / Q000302:isolation & purification*; D013045:Species Specificity
D003470:Culture Media