The Family Enterobacteriaceae

The Family Enterobacteriaceae
Student’s Name
Institutional Affiliation
Enteric Pathogens
Enteric pathogens are microbes that affect the intestines and can cause infections.
The reason why Anaerobic Pathogens are Invisible in Regular Fecal Specimen
Bacteria should not contaminate specimens. Materials that are sterile like spinal fluid and blood have no problem, provided the relevant precautions are followed to properly decontaminate the skin before it is punctured to acquire the specimen. Fecal specimens cannot be cultured regularly for pathogenic anaerobes since they usually have other anaerobic microbes (Hentges, 2019). Due to this, aspirates from abscesses or specific infection locations must be obtained to prevent undue contamination with native flora elements.
Description of Indole Tests, Methyl Red Test, Voges-Proskauer Test and Citrate Test
Indole Test
The test illustrates the ability of specific bacteria to break down tryptophan to indole. It is used as a portion of the IMViC processes, a test established to differentiate the members of the family Enterobacteriaceae. The main ingredient in the test is sufficient tryptophan (Hentges, 2019). The formation of a pink to red color in the reagent layer indicates positive results for an indole test. In contrast, the absence of any change in color after adding the appropriate reagent signifies a negative result.
Methyl Red (MR) Test
The test discovers whether adequate acid is formed when glucose is fermented and how to maintain conditions for the pH of old culture to remain below 4.5, as indicated by variation of methyl red indicator color introduced at the end of the incubation period (Aryal, 2018a). A positive MR test is displayed when the red color is formed when the methyl red indicator is introduced. On the other hand, a negative result is indicated by a yellow color.
Voges-Proskauer (VP) Test
The test determines whether microbes generate acetyl methyl carbinol after glucose is fermented. It discovers microbes utilizing butylene glycol track to form acetoin. VP reagents are merged with MR-VP broth, which has been infused with an organism using a butylene glycol track (Aryal, 2018). The final product is oxidized in the company of potassium hydroxide to form diacetyl. Creatine is also present to speed up the reaction. Diacetyl reacts to form a...