1. Elona Mavashev
Microbiology 351 Lab
James Major
Unknown
Unknown
Introduction
Bacteria have been around for many centuries. It is found in our every day life. There
are many reasons for discovering the uniqueness of microorganisms. The main purpose
of identifying an organismis to diagnosis symptoms that are caused by the bacteria.
Identifying a pathogenic microorganism can allow for advances in medicine, which can
then potentially help save lives. Strepococcus Pyogenes is one of the most common
pathogens of humans. Some diseases associated with this organism are scarlet fever,
pauerpael fever, pharyngitis, and many more diseases. It is a very life threating bacteria.
The morphology of this organism is spherical with chain-like formations (Herriman,
2011). It stains purple, which means it’s Gram positive. This species could appear as a
pearl necklace when seen under a microscope (Herriman, 2011). This is usually found in
the mouth and respiratory system. The most common name for this is strep throat. This
is easily spread from person to person. When a culture is taken on from a person’s
throat and put on a blood agar, the culture should have a clearing zone, which indicates
beta hemolysis. Streptococcus Pyogenes is very sensitive to penicillin (Bessen, 2010).
Strep throat is a common bacterial infection in the throat. This could be a pre
indicator to a more serious condition like scarlet fever (savage et al 2005). This disease
affects agriculture due to the fact some dogs, cats and rabbits are able to get the

2. infection only as carriers and spread it to others (Bessen, 2010). Since these animals
roam around farms and ranches it can affect the food, which can then affect humans.
In my unknown tests my bacteria had abnormalities, but they were consistent
with findings from previous literature. In a previous study this bacteria had uniqueness
when under certain conditions. Some conditions “did not support persistence, these
cells disappeared 2 weeks after loss of culturability. In persistent cultures, these maybe
cells that are dying during turn over” (Wood et al, 2005). This would explain why the
bacteria I tried the first time were dead. The streptococcus pyogene within these
conditions gives a better understanding of why a streak would show small colonies.
Some had common changes that would occur, “many in which were unique to a single
strain. Some of the common changes were in metabolic pathways, suggesting a possible
alternate metabolism for the persisters. Overall, these data suggest that under certain in
vitro conditions, S. pyogenes cells can persist for greater than 1 year as a dynamic
population” (wood et al, 2005). The results from this study help clarify why some
streptococcus would appear small on an agar plate. More studies have to be done in
order to determine why streptococcus pyogenes causes small colonies and what other
conditions could affect it.
Many different studies have been performed with streptococcus. An interesting
study revealed that pharyngitis is a really common disease that occurs in school-aged
children. Within the study the scientist isolated Chinese children. The results came out
to be that “among the s. pyogenes strains causing pharyngitis in Chinese children, 13
different emm types were identified; emm1 and emm 12 types were more prevalent

3. and were found to be 84.9 % of all strains” (Chang et al 2011). This is important because
if a doctor is able to determine the different strains, then they can treat them
accordingly. The results from the study could show a possibility that different minorities
could have more strains. More research has to be done to see if races other than
Chinese are isolated with different strains as well.
Results and Rational
My unknown number I picked was 28. When I did the gram stain I did on a slide with my
partner. My grain stain was very unclear. When I did it again I was able to see very little
color of gram-positive coccus. When I streaked it nothing grew. Since it did not grew on
the regular agar. I tired streaking again on a brain heart infusion agar. My results the
first time where inclusive, my bacteria ended up being dead. I ended up having to have
a new broth made. When I got the new broth I streaked it on the regular agar and my
results where that I got really small colonies. I was worried that since my colonies were
small that they were not growing properly. I restreaked on a brain heart infusion agar. I
restreaked on this agar because it is more nutrient aspect to help the organism grow
better. The results ended up as very small colonies again. Look at figure to see results.
These results were abnormal from what normal colonies look like. Good growths of
colonies are vast majority of round organism that is isolated within agar. From there I
performed a catalase test. The results of the catalase was negative no bubbles were
present. This means that the unknown bacteria did not have any catalase present. “This
test is to detect an enzyme that detoxifies hydrogen peroxide produces in the aerobic
ETC” (Leboffe et al, 2011). The test indicated a negative result. The next step from that

4. was to verify. The first test I did to verify it was the unknown tested on the mannitol salt
agar. Look at figure 2 to see results. This is to inhibit growth od gram positive when
cultivated together. This is used to isolate streptococci and straphylococci in a human
sample. The results of this showed no growth. If the test-exhibited growth it would of
showed that the organism is inhibiting NaCl. With the test being negative the organism
does not ferment mannitol because there was no reaction. The last test I performed was
the blood agar test. This test is suppose to help “indicate cultivate fastidious
microorganism and to detect bacterial hemolytic ability.the results of this test can be
seen in figure 3. The coagulase tests are commonly used to presumptively identify
pathogenic staphylococcus species”( Leboffe et al, 2011).
Figure 1. The streak on the TSA Plate small colonies, which equaled abnormal results

5. Figure 2. This is a negative test for confirmation of Mannital salt agar
Figure 3. Beta Hemolysis is a positive test of streptococcus Pyogenes
Conclusion
My unknown is streptococcus Pyogenes.

6. Reference
Retrieved from characteristics of streptococcus pyogenes on 4/18/14
fromhttp://www.livestrong.com/article/82105-characteristics-streptococcus-
pyogenes/
Daniel N. Wood, Michelle A. Chausse, Michael S. Chausse and Bettina A. Buttarol
(May, 2005) Persistence of Streptococcus pyogenes in Stationary- Phase cultures, j.
Biology (http://jb.asm.org/content/187/10/3319.full#corresp-1)
References appearing as e-pubs should be in the following style: Debra E. Bessen,( July
1, 2010) Population Bilogy of the Human Restricted Pathogen, Streptococus Pyogenes,
Pub med.
Retrieved from characteristics 4/18/14 from http://web.clark.edu/tkibota/240/Di
sease/StrepThroat.pdf
Hesheng Chang,, Xuzhuang Shen Guoying Huang, Zhou Fu, Yuejie Zheng, Libo Wang,
Chengrong Li Lan Liu Ying Shen, Xiaorong Liu, Yonghong Yang (2011) Molecular
analysis of a Streptococcus pyogenes strain is isolated from Chinese children with
pharyngitis. Diagnostic Microbiology and Infection Disease, 117-122