Microbes In Microbiology

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Introduction
Identifying microbes are important for working in the medical fields and also for research. Physical and cellular processes are ways in which microbes can be identified. A series of test were done to identify an unknown microbe labeled 5. Based on observation and the results conclusion was made to identify the bacteria as Enterobacter aerogenes.
In microbiology, researchers are frequently trying to culture and classify microorganisms in a laboratory setting for study. Because of this there are now numerous test that can be used to identify unknown microbes. In this experiment, morphological characteristics, biochemical and gram staining test were used to identify unknown 5.
These tests are important because most microbes are comparable
…show more content…
The oxidase agent was added to a sample of the microbes on the cotton swab. A color change to purple was observed, meaning the microbe was positive for this test. Bubbles were detected in the catalase test, meaning the test was positive. After the addition of reagent A and B there was no color change, thus the microbes do not reduce nitrate. For the hydrolytic test, the starch plate had highlights around the bacterial growth indicating starch hydrolysis. In the fat containing plate there was no dark pigment, meaning enzyme wasn’t made. The casein test had no clear zones, meaning casein wasn’t degrade. For the Tryptophan degradation, no red was detected on top of the medium, which indicated that it was negative. Urea hydrolysis test was also negative no color change to pink was detected. This means that there was no urea hydrolysis and the organism does not produce urease or cannot live in broth. Phenylalanine deamination test was negative meaning the slant didn’t change to green. For the hydrogen sulfide production test, it was negative since the strip didn’t turn black. Overall, based on results gather unknown 5 was identified as Enterobacter aerogenes because the methyl red test was positive and the urea test was negative. And the H2S production test was negative, leaving with only E.coli and Enterobacter aerogenes. Since the indole test was negative this eliminated E.coli and Enterobacter …show more content…
It also has an resistance to β-lactam antibiotics during therapy (3). A 60 year old woman had an infection caused by E. aerogenes. During her treatment the bacteria was resistant to imipenem during treatment through a decrease in porin synthesis(3). Because of that she was then given different antibiotic atleast every month to see what was the right antibiotic.
Antibiotics used in this study includes: imipenem, cefepime, ceftazidime, colistin, polymyxin B, norfloxacin, ciprofloxacin, cotrimoxazole, and gentamicin (3). All the above antibiotics were used on the patient but still E. aerogenes had a strong resistance to all of the antibiotics used. The patient condition remain stable for ten days and right after the patient died from multiple or gan failure that was associated with septic shock (3).
In conclusion based on results gather unknown 5 was identified as Enterobacter aerogenes because the methyl red test was positive and the urea test was negative. And the H2S production test was negative, leaving with only E.coli and Enterobacter aerogenes as a choice. Since the indole test was negative this eliminated E.coli and Enterobacter aerogenes is

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