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Introduction
Introduction
Streptococcus pyogenes is a group A streptococcus and is considered to be a human pathogen. It grows in chains and causes numerous infections in humans including pharyngitis, tonsillitis, scarlet fever, cellulitis, erysipelas, rheumatic fever, post-streptococcal glomerulonephritis, necrotizing fasciitis, myonecrosis and lymphangitis.
Taxonomy
Taxonomy
Kingdom: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Lactobacillales
Family: Streptococcaceae
Genus: Streptococcus
Species: pyogenes
Growing Streptococcus pyogenes
Growing Streptococcus pyogenes
How do you grow it?
What is the BSL level for your microbe?
Streptococcus pyogenes has a BSL level of 2.
What type of agar do you need?
Streptococcus pyogenes will need Brain Heart Infusion Agar and Trypticase soy agar with defibrillated sheep blood.
Does it need to be in aerobic/anaerobic conditions?
My microbe is a catalase-negative aerotolerant anaerobe, thus is suited for anaerobic conditions. The atmospheric condition for growth is 5% CO2.
What is the procedure for growing it once it arrives?
The procedures to grow my microbe once it arrives are:
Open the vial according to enclosed instructions.
Using a single tube of Brain Heart Infusion broth (5 to 6 mL), extract about 0.5 to 1.0 mL with a pipette.
Rehydrate the entire pellet.
Aseptically transfer this aliquot back into the broth tube and carefully mix.
Use several drops of the suspension to inoculate a Trypticase soy agar slant.
Incubate the tubes and plate at 37˚C for 24 hours in an atmosphere of 5% CO2.
When was the first documentation of it? Who discovered it?
My microbe was first documented in 1894 and was discovered by Arthur Howard Mann Jr.
visualize Streptococcus pyogenes
visualize Streptococcus pyogenes
This image is the visualization I found of my microbe Streptococcus pyogenes.
This image here shows Streptococcus pyogenes in a gram stain. The purple color tells us that this is Gram-positive. The morphology of my microbe is coccus.
Above, the Streptococcus pyogenes is visualized on a scanning electron microscope (SEM) and is not gram stained.
Above, the microbe is visualized on a transmission electron microscope (TEM) and is not gram stained.
diagnostic tests
diagnostic tests
After using GIDEON, I determined that the tests that I would need to use to identify my microbe (Streptococcus pyogenes) would be testing for gram positive, coccus – pairs or chains predominate, cephalothin-susceptible, beta hemolysis, pyrrolidonyl-beta-naphthylamide, and alkaline phosphatase. These tests gave a 100% result for Streptococcus pyogenes.
Gram Stain
Gram Stain
A gram stain is used to test for the presence of peptidoglycan within the cell wall of a given microbe. This test results in either a positive or a negative. This image of Streptococcus pyogenes illustrates that it is a gram positive because it is stained in a purple color, showing that it will have peptidoglycan in its cell wall.
Coccus Shape
Coccus Shape
Bacteria are usually categorized by their shape. To test for their shape, study the microbe under a microscope and analyze its shape and pattern. As seen in this image, Streptococcus pyogenes is in a coccus shape because it is spherical. Specifically, this microbe is coccus that predominately aligns in pairs and chains.
Hemolysis Testing (Blood Agar)
Hemolysis Testing (Blood Agar)
To test for hemolysis, we need to perform a streak on a blood agar plate. Some microbes produce exotoxins known as hemolysins which destroy hemoglobin and red blood cells. In this image, Streptococcus pyogenes results in clearing of the blood agar medium with the bright yellow streaks, illustrating that is conducts beta-hemolysis. Beta-hemolysis means that it can completely kill, or lyse, red blood cells.
Cephalothin susceptibility
Cephalothin susceptibility
A cephalothin susceptibility test is utilized to learn whether the cephalothin antibiotic would inhibit the growth of a specific microbe. As seen in the picture, the areas with the cephalothin inhibit the growth of the Streptococcus pyogenes, thus illustrating that it is positive for cephalothin-susceptibility. This is important because it allows us to know which antibiotics will be able to treat people who are infected.
Pyrrolidonyl-beta-naphthylamide (PYR)
Pyrrolidonyl-beta-naphthylamide (PYR)
The Pyrrolidonyl-beta-naphthylamide test (PYR) is utilized to identify of the group A beta-hemolytic Streptococci and is also useful in differentiating various Enterococcus bacteria. It also can help monitor the activity of the enzyme L-pyrroglutamyl amino-peptidase which is specifically produced by Streptococcus pyogenes. As seen in the picture, Streptococcus pyogenes would be positive in this test because it would turn the liquid red. This means that it does contain the enzyme and beta-hemolytic groups as explained above.
Alkaline phosphatase (ALP) Test
Alkaline phosphatase (ALP) Test
This alkaline phosphatase (ALP) test indicates and measures how much alkaline phosphatase is leaked into the blood stream. ALP is an enzyme found throughout the body, however, when the liver is damaged ALP leaks into the bloodstream. As seen in the picture, Streptococcus pyogenes is shown to be positive for ALK because it colorized as bright blue. This illustrates that the enzyme ALP and Streptococcus pyogenes interact and thus shows that Streptococcus pyogenes may cause damage to the liver and blood.
disease and treatments
disease and treatments
Is it a pathogen? What disease does it cause? Or does it have any benefits to the host? How can infection or contraction of the disease be prevented?
Streptococcus pyogenes is regarded as a gram-positive bacterial pathogen that causes a large variety of clinical conditions. Some of the diseases that this pathogen causes are scarlet fever, bacteremia, pneumonia, necrotizing fasciitis, myonecrosis, and Streptococcal Toxic Shock Syndrome (StrepTSS). The most effective way to prevent infection or contraction of this disease is frequent handwashing.
Where is it traditionally found?
This microbe is exclusively a human pathogen and is traditionally carried by approximately 5 to 15% of humans in the nasopharynx and oropharynx.
Why do people care about it? Is there a commercial or ecological application, other oddities about your adopted microbe?
Streptococcus pyogenes is significant because it is a global pathogen that is responsible for causing a multitude of infections, some of which are severely life threatening.
What Antibiotics work against your bacteria? Are there any other treatments for it?
The most effective antibiotics that work against Streptococcus pyogenes are penicillin and amoxicillin. There has not been a report of an isolated strep strand from Streptococcus pyogenes that is resistant to penicillin.
Molecular Diagnostic
Molecular Diagnostic
The primers I found for Streptococcus pyogenes were:
Forward
· Str1 [5′-GTACAGTTGCTTCAGGACGTATC-3′]
· Melting Temperature: 55.3˚C
· GC Content: 48%
Reverse
· Str2 [5′-ACGTTCGATTTCATCACGTTG-3′]
· Melting Temperature: 50.5˚C
· GC Content: 43%
The specific 16s sequence (in FASTA format) for Streptococcus pyogenes is:
>FJ662832.1 Streptococcus pyogenes strain Sp16 16S ribosomal RNA gene, complete sequence
GAGTTTGATCCTGGTTCAGGACGAACGCTGGCGGCGTGCCTAATACATGCAAGTAGAACGCTGAGAACTG
GTGCTTGCACCGGTTCAAGGAGTTGCGAACGGGTGAGTAACGCGTAGGTAACCTACCTCATAGCGGGGGA
TAACTATTGGAAACGATAGCTAATACCGCATAAGAGAGACTAACGCATGTTAGTAATTTAAAAGGGGCAA
TTGCTCCACTATGAGATGGACCTGCGTTGTATTAGCTAGTTGGTGAGGTAAAGGCTCACCAAGGCGACGA
TACATAGCCGACCTGAGAGGGTGATCGGCCACACCGGGACTGAGACACGGCCCAGACTCCTACGGGAGGC
AGCAGTAGGGAATCTTCGGCAATGGGGGCAACCCTGACCGAGCAACGCCGCGTGAGTGAAGAAGGTTTTC
GGATCGTAAAGCTCTGTTGTTAGAGAAGAATGATGGTGGGAGTGGAAAATCCACCAAGTGACGGTAACTA
ACCAGAAAGGGACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTCCCGAGCGTTGTCCGGATT
TATTGGGCGTAAAGCGAGCGCAGGCGGTTTTTTAAGTCTGAAGTTAAAGGCATTGGCTCAACCAATGTAC
GCTTTGGAAACTGGAGAGCTTGAGTGCAGAAGGGGAGAGTGGAATTCCATGTGTAGCGGTGAAATGCGTA
GATATATGGAGGAACACCGGTGGCGAAAGCGGCTCTCTGGTCTGTAACTGACGCTGAGGCTCGAAAGCGT
GGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGAGTGCTAGGTGTTAGGCCCTT
TCCGGGGCTTAGTGCCGGAGCTAACGCATTAAGCACTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACT
CAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCT
TACCAGGTCTTGACATCCCGATGCCCGCTCTAGAGATAGAGTTTTACTTCGGTACATCGGTGACAGGCGG
TGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCCTATTGT
TAGTTGCCATCATTAAGTTGGGCACTCTAGCGAGACTGCCGGTAATAAACCGGAGGAAGGTGGGGATGAC
GTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGTTGGTACAACGAGTCGCAAG
CCGGTGACGGCAAGCTAATCTCTTAAAGCCAATCTCAGTTCGGATTGTAGGCTGCAACTCGCCTACATGA
AGTCGGAATCGCTAGTAATCGCGGATCAGCACGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGC
CCGTCACACCACGAGAGTTTGTAACACCCGAAGTCGGTGAGGTAACCTATTAGGAGCCAGCCGCCTAAGG
TGGGATAGATGATTGGGGTGAAGTCGTAACAAGGTAGCCGTAATCGGA
About the researcher
About the researcher
Hello everyone, my name is Omar Elrabi and I am a third year Microbiology major on the pre-dental track. I am originally from Tampa, Florida and have lived there for most of my life. In my free time, I enjoy watching movies, tv shows, and playing video games. I also love playing basketball and soccer with friends.
references
references
Mann AH. 1894. A CASK OF EMPHYSEMATOUS GANGRENE OF THE HAND DUE TO THE STREPTOCOCCUS PYO-GENES AND THE BACILLUS ERO-GENES CAPSULATUS: RECOVERY WITHOUT AMPUTATION. Annals of Surgery 19:187–196.
Severin A, Nickbarg E, Wooters J, Quazi SA, Matsuka YV, Murphy E, Moutsatsos IK, Zagursky RJ, Olmsted SB. 2007. Proteomic Analysis and Identification of Streptococcus pyogenes Surface-Associated Proteins. JB 189:1514–1522.
Low, D. (2019, January 19). Streptocococcus pyogenes. Retrieved December 02, 2020, https://www.infectiousdiseaseadvisor.com/home/decision-support-in-medicine/infectious-diseases/streptocococcus-pyogenes/
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