Microbiology: Diagnosis of an Infected Patient (Essay Sample)

Diagnosis of an Infected Patient
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The staining procedures used to differentiate the types of bacteria are known as differential technique of staining. The simple methods of staining impart same color to all types of bacteria and other biological materials. The principle behind this differentiation is due to the variation in physical and chemical properties of the cell. Consequently, reaction occurs differently to reagents.
In handling of the sputum when testing for the presence of bacteria pathogen one has to ensure that there is no extraneous bacteria to contaminate the specimen. The sample is refrigerated for a maximum of twenty-four hours. The sample should not be frozen or stored at room temperature. Ensure that the minimum amounts of the present antibiotics that inhibit bacterial growth are not visible to the eye. One should differentiate pathogenic and normal flora bacteria. The identification of the bacteria is a step by step process that involves biochemical, molecular and immunological tests and observations.
To determine the viable bacterial numbers in the sputum sample, the sample is homogenized with dithiothreitol and glass beads in order to determine the method which recovered the greatest number of viable bacteria. Continuous monitoring systems of mycobacterium report higher contamination rates than traditional radiometric technologies. The first step in analyzing fresh sputum is the gram stain test which seeks to identify the type of bacteria in the sample. If the sample is seen to contain a lot of normal cells then the sample is unworthy for testing and a recollection should be done. If the sample contains a lot of white blood cells then the sample qualify for culturing.
Once the sample has been accepted, it is placed on nutrient media that check the sample and encourages bacteria to grow and allows further identification and testing. The next step is usually to identify the different bacteria present and categorize them as potential or normal disease causing bacteria. Antimicrobial susceptibility testing is usually used to identify the bacteria that cause diseases and find out the likelihood of the bacteria to respond to antibiotics.
Different types of staining techniques are used in making cells and their respective internal structures to have more visibility under the light microscope. Different stains possess varying affinities for different organisms, or rather different organisms’ parts. They are used in the differentiation of different types of organisms or viewing of organisms’ specific parts. Staining is a microscopic auxiliary technique used in the enhancement of microscopic image. Stains and dyes are often used in biology in the highlighting of structures in biological tissues with the aim of viewing aided by different microscopes.
The staining techniques used in the identification of unknown samples are the acid fast staining techniques (AFB). A good example of acid-fast bacilli are the mycobacteria. They are gram resistant, non-motile and pleomorphic rods which are related to the Actinomyces. The stains that are used in most cases are the Carbol Fuchsin that are red colored which stain the bacteria and a counter stain like Malachite green or Methylene blue. AFB methods include Zeihl-Neelsen’s-hot stain and Kinyoun’s-cold stain.
The Ziehl-Neelsen procedure involves spreading the sputum evenly over the central area of the slide using a continuous rotational movement. The slides are placed on dryer with the smeared surface upwards and the dried smear is heat fixed till the immediate rising of vapor when the stain is washed with clean water. For a duration of two to five minutes, the smear is covered with 3% v/v alcohol until it turns to pale pink, then wash it well with clean water. The stain is then covered with malachite green stain for one to two minutes and then washed off with clean water. Thereafter, it is wi...