A single-tube screen for Salmonella and Shigella.
Salmonella and Shigella species are routinely sought in stool specimens submitted for culture. It is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and Christensen urea agar to determine if further identification is necessary. We designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent Salmonella or Shigella. We tested this media combination with 106 Salmonella, 56 Shigella, and 56 other gram-negative bacilli. All Salmonella and Shigella isolates tested were appropriately characterized as possible Salmonella or Shigella by using an algorithm developed for use with this media combination. Similarly, 53 (95%) of 56 other gram-negative bacilli were appropriately screened as non -Salmonella and non -Shigella isolates. This unique media combination provides the most important biochemical reactions needed to screen for Salmonella and Shigella in a single-tube format, which decreases labor by two thirds (ie, 1 tube is inoculated vs 3).
Procop
Gary W
GW
Section of Clinical Microbiology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Wallace
Jacqueline D
JD
Tuohy
Marion J
MJ
Lasalvia
Margret M
MM
Addison
Rachel M
RM
Reller
L Barth
LB
D000362:Agar; D000465:Algorithms; D001431:Bacteriological Techniques; D003470:Culture Media; D006088:Gram-Negative Aerobic Bacteria / Q000302:isolation & purification; D012475:Salmonella / Q000302:isolation & purification*; D012760:Shigella / Q000302:isolation & purification*
D003470:Culture Media; D000362:Agar