Microbiology Study: Identification of Unknown Organisms from Bacterial Cultures

Running head: MICROBIOLOGY
Topic: MICROBIOLOGY
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1MICROBIOLOGY
Introduction
The following studies are conducted with the primary aim of identification of
unknown organisms from the given bacterial cultures. From the materials and methods of the
following practices, determination of microorganism and their ability of growing on various
selective media will be determined. Such ability of growth often acts as an indication of the
vivid properties pertaining to physiology and morphology of the organisms which include
gram negative as well as gram positive organisms. Some organisms also have shown the
property of changing their shapes under various conditions thus showing the phenomenon of
pleiotropy which is absent in the samples taken. Colony morphology is another important
characteristic which will be determined from the following experiments. These practical also
deal with determination of the gram character of the organisms pertaining to microscopy.
Bacterial cultures are usually different according to their biochemical properties as well as
cellular shapes. Biochemical properties is another area of determination of the
microorganisms which will be gradually determined with the help of various tests. Analytical
profile index have been used for the identification of the bacteria. It is a classification of
microorganism which is based on various experiments allowing quick identification. The
system facilitates the identification of bacterial species which are clinically relevant. This
system has been developed first by Pierre Janine and mainly is a miniaturized version
inclusive of identification of a number of Streptococci. It allows the identification of various
gram negative bacteria. For identification of the microorganisms they have been grown in
blood agar which is an enriched medium ideal or bacterial growth .The use of blood agar
helps in the process of hemolysis which is important for the subsequent steps an d it increases
the growth of various Streptococci apart from the growth on catalase The most cultures for
identification of streptococcus has been oral and throat cultures (Speller erg and Brandt.
2016). Moreover, fastidious bacteria are not known for growing in required media blood agar

2MICROBIOLOGY
which is usually known for the growth of Streptococci strains. Aerobic or anaerobic bacteria
are also a major source of differential growth in medium in this context (Dionne et al. 2016).
Blood is usually inhibitor for the growth of organisms like Hemophilic as well as Neisseria.
The given blood agar should be heated in order to inactivate the inhibitors and for the releases
of essential growth factors although excess heating converts it to chocolate agar where the
growth of Streptococci like strains will be encouraged (microbeonline.com, 2019). Thus the
various process like growth of culture medium in differential as well as staining procedure
followed by API test for Streptococci have been performed for the growth of the given
bacteria and their subsequent identification of organisms (biomerieux-usa.com, 2019).
Moreover easy surface checking (ESC) has been done with swab range inclusive of a number
of sampling devices which are used for mainly examining the microbiological surface of the
aforementioned microorganisms,. These kind of tests are mainly used for the pharmaceutical
and food industries. They give accurate results and convenient to use at room temperatures.
In the given practical Streptococcus species have been apprehended as the identifiable
organisms which are mainly found in infections pertaining to tooth decay as they are common
inhabitants of the oral cavity (Aziza et al. 2016).
Materials and methods
The whole practical was done in four phases and the results were recorded within 4
days after observing the results.
For the first day, experiments were performed regarding growth of the organisms in
various media to check in which media the growth of microorganisms were seen. It was
implemented using blood agar as it is a differential media allowing the growth of organisms
like Streptococci which has been apprehended as the observable strains. Growth of the
organism is essential for separating the bacteria among the rest of the bacterial cultures. The
dilution stock has been taken and dilutions have been done in reference to the mother culture.