Enterobacter Agar Lab Report

All of the isolates shown in Table 1 were resistance to S. aureus and were considered antibiotic producers. However, only isolate 12 and 16 showed resistant to the unknown Gram-negative organism. All of the antibiotic producers were then tested against Enterococcus faecalis, Pseudomonas putida, Acinetobacter baylyi, Escherichia coli, and Enterobacter aerogenes by the streak-plate method, which can be seen in Table 2.
As demonstrated in Table 2, none of the antibiotic producers were found to be resistant against Enterococcus faecalis or Pseudomonas putida. Table 2 also showed isolates 3 and 4 were resistant to Acinetobacter baylyi, isolate 12 was resistant to Escherichia coli, and isolates 12 and 16 were resistant to Enterobacter aerogenes. …show more content…
Therefore, the isolate was tested on EMB agar, a selective and differential media that inhibits the growth of most Gram-positive organisms and can determine if an isolate is a lactose fermenter. If the isolate were a lactose fermenter this would be indicated by a dark color change in the colonies that formed. The EMB test results showed isolate 6B to form a metallic dark blue color, which, indicated isolate 6B was most likely a Gram-negative organism and a lactose fermenter. To ensure isolate 6B was a lactose fermenter, a test on MacConkey agar was performed. MacConkey agar is also a selective and differential media that inhibits the growth of Gram-positive organisms and determines if the organism ferments lactose. A positive result for lactose fermentation would be indicated if the bacterial smear turned pink. After incubation, isolate 6B grew on the MacConkey agar and turned pink, which indicated isolate 6B was a Gram-negative lactose fermenter. The next test performed was on blood agar, which tested the organism’s hemolytic capabilities. When isolate 6B was streak plated onto the blood agar, colonies formed, this indicated the isolate had hemolytic capabilities. A phenol red