A method of detecting Salmonella microorganisms, the method comprising: providing, a sample to be tested; a culture device; a nutrient medium that facilitates growth of a Gram-negative enteric microorganism; a first selective agent that inhibits the growth of Gram-positive microorganisms; a first differential indicator system comprising a first differential indicator compound that can be converted to a first detectable product by a member of a group of Salmonella microorganisms that includes a microorganism of the species Salmonella bongori; and a second differential indicator system comprising a second differential indicator compound that can be converted to a second detectable product by a β-galactosidase enzyme activity; contacting in the culture device the nutrient medium, the first selective agent, the first differential indicator system, and the second differential indicator system with a sample to form an inoculated culture device; incubating the inoculated culture device for a first period of time at a temperature greater than 40 degrees C; observing the culture device to detect a presence or an absence of the first detectable product; and observing the culture device to detect a presence or an absence of the second detectable product; wherein observing the presence of the first detectable product indicates a possible presence in the sample of a Salmonella microorganism; wherein observing the presence of the first detectable product juxtaposed with the second detectable product indicates a presence in the sample of a microorganism other than a β-galactosidase-producing member of the species Salmonella bongori. providing, a sample to be tested; a culture device; a nutrient medium that facilitates growth of a Gram-negative enteric microorganism; a first selective agent that inhibits the growth of Gram-positive microorganisms; a first differential indicator system comprising a first differential indicator compound that can be converted to a first detectable product by a member of a group of Salmonella microorganisms that includes a microorganism of the species Salmonella bongori; and a second differential indicator system comprising a second differential indicator compound that can be converted to a second detectable product by a β-galactosidase enzyme activity; a sample to be tested; a culture device; a nutrient medium that facilitates growth of a Gram-negative enteric microorganism; a first selective agent that inhibits the growth of Gram-positive microorganisms; a first differential indicator system comprising a first differential indicator compound that can be converted to a first detectable product by a member of a group of Salmonella microorganisms that includes a microorganism of the species Salmonella bongori; and a second differential indicator system comprising a second differential indicator compound that can be converted to a second detectable product by a β-galactosidase enzyme activity; contacting in the culture device the nutrient medium, the first selective agent, the first differential indicator system, and the second differential indicator system with a sample to form an inoculated culture device; incubating the inoculated culture device for a first period of time at a temperature greater than 40 degrees C; observing the culture device to detect a presence or an absence of the first detectable product; and observing the culture device to detect a presence or an absence of the second detectable product; wherein observing the presence of the first detectable product indicates a possible presence in the sample of a Salmonella microorganism; wherein observing the presence of the first detectable product juxtaposed with the second detectable product indicates a presence in the sample of a microorganism other than a β-galactosidase-producing member of the species Salmonella bongori.