Isolation and Antibiotic Resistance Testing of Delftia acidovorans from Organic Lettuce
Pa Kou Thor
Introduction
Organic foods continue to be a health choice trend for many United States Americans as they are seen as the healthiest, natural and raw choice of food. However, there has been a growing concern of having antibiotic resistance bacteria existing on fresh organic produce. This combats the long-term thought that organic food, being free of chemicals and antibiotics, would not have bacteria developing resistance. However, in Wadamori, et al., preliminary study indicated that the microbial risk of fresh produce collected from an organic farm was higher than the fresh produce from a traditional farm (1). The danger lies mostly in the use of compost and manure as natural fertilizer since compost is a mixture of organic waste and animal manure which contains abundant amounts of fecal coliforms (1).
In this experiment, the isolate bacteria found was the Delftia acidovorans (D. acidovorans) which was formerly known as Comamonas acidovorans. They could be commonly found in soil and water …show more content…
acidovorans (2) matched the isolate bacteria; however, blast sequence only identified a highest of 88% 16S rRNA gene with max score base match of 636 bases. For a significant identification, 97% value would be needed. The MIC assay showed the isolate being resistant to all concentrations of ampicillin as the bacteria grew and formed biofilms in each one. For the DDA, the isolate bacteria did not grow abundantly throughout the ampicillin or the positive control as expected, although, it did have susceptibility to ciprofloxacin. However, this susceptibility became weaker as the first DDA was incubated for a longer period and a few colonies grew in the ciprofloxacin zone of inhibition. A key indicator of D. acidovorans would be the indole test, because of orange color that was release because of anthranilic acid being produced from tryptophan
Pa Kou Thor
Introduction
Organic foods continue to be a health choice trend for many United States Americans as they are seen as the healthiest, natural and raw choice of food. However, there has been a growing concern of having antibiotic resistance bacteria existing on fresh organic produce. This combats the long-term thought that organic food, being free of chemicals and antibiotics, would not have bacteria developing resistance. However, in Wadamori, et al., preliminary study indicated that the microbial risk of fresh produce collected from an organic farm was higher than the fresh produce from a traditional farm (1). The danger lies mostly in the use of compost and manure as natural fertilizer since compost is a mixture of organic waste and animal manure which contains abundant amounts of fecal coliforms (1).
In this experiment, the isolate bacteria found was the Delftia acidovorans (D. acidovorans) which was formerly known as Comamonas acidovorans. They could be commonly found in soil and water …show more content…
acidovorans (2) matched the isolate bacteria; however, blast sequence only identified a highest of 88% 16S rRNA gene with max score base match of 636 bases. For a significant identification, 97% value would be needed. The MIC assay showed the isolate being resistant to all concentrations of ampicillin as the bacteria grew and formed biofilms in each one. For the DDA, the isolate bacteria did not grow abundantly throughout the ampicillin or the positive control as expected, although, it did have susceptibility to ciprofloxacin. However, this susceptibility became weaker as the first DDA was incubated for a longer period and a few colonies grew in the ciprofloxacin zone of inhibition. A key indicator of D. acidovorans would be the indole test, because of orange color that was release because of anthranilic acid being produced from tryptophan