Shigella and the majority of salmonellae Clear, colorless, transparent Salmonella enteriditis ATCC 13076 Colorless with black center Salmonella typhi ATCC 6539 Colorless with black center Salmonella typhimurium ATCC 14028 Colorless with black center
Salmonella, Shigella, Yersinia, and Serratia are all gram-negative facultatively anaerobic rods.
salmonella
Salmonella, Shigella Organisms that ferment lactose display "nucleated colonies" - colonies with dark centers.
Its color is red.
MacConkey agar: Selective for Gram-negative bacteria, inhibits the growth of Gram-positive bacteria. Hektoen enteric agar: Selective for Gram-negative enteric pathogens, such as Salmonella and Shigella species. Thiosulfate-citrate-bile salts-sucrose (TCBS) agar: Selective for Vibrio species, especially Vibrio cholerae. Cefsulodin-irgasan-novobiocin (CIN) agar: Selective for Yersinia species.
urease - negative ONPG - positive Lysine - positive
S. aureus, E. coli, P. auriginosa, Salmonella typhi, Shigella sonnei, Shigella flexneri, Vibrio cholera.
Mnemonic: KEE Klebsiella pneumoniae Enterobacter cloacae E. coli Shigella sonnei can ferment lactose, but only after prolonged incubation and so it is referred to as a '''''late-lactose fermenter'''''. Vibrio cholerae is also a late lactose fermenter.
Shigella, Salmonella, Campylobacter, and Yersinia. Clostridium difficile produces a toxin that can cause severe diarrhea.
Shigella is a genus of Gram-negative, facultative anaerobic, non-spore-forming, non-motile, rod-shaped bacteria closely related to Salmonella. Non-motile means that it doesn't move, so no flagella.
MacConkey agar is designed to grow Gram-negative bacteria and also contains crystal violet dye which inhibits the growth of Gram-positive bacteria. Since S. aureus is Gram-positive it should not grow on MacConkey agar. No. MacConkey agar inhibits MOST of the Gram-positive bacteria. There are some Gram-positive bacteria that can tolerate bile-salt are able to grow in MacConkey agar. Enterococcus and some species of Staphylococcus are able to grow in MacConkey. (lack citation though)