Macy Gagne
12/6/14
Microbiology 83414
Angelo Kolokithas
Streptococcus pyogenes There are trillions of bacteria on earth. It is hard to believe that something so small can be so destructive. Bacteria replicates so fast that small symptoms can soon turn way worse, sometimes can even cause death. In fact bacterial infections are the number one cause for death in the United States in young children and elderly adults (Streptococcal Infections).
The unknown I was given was unknown number four. The tests I did helped me conclude that the organism unknown number four is Streptococcus pyogenes. The fist step I did when getting the unknown organism was Gram stain it to determine whether it was gram-positive or gram-negative. Viewing the organism …show more content…
After I found that the unknown is gram-positive I performed a catalase test, which presented negative results because no bubbling appeared. The appearance of no bubbles signified that the organism is streptococcus. Following the catalase test I observed the hemolysis of the organism, which signified beta-hemolysis because I could see all the way through the blood agar. Knowing that the unknown is beta-hemolytic lead me to choose to perform a bacitracin test. After letting the organism incubate I observed the plate and saw that there wasn’t any growth right up to the bacitracin disc, but the was growth about a centimeter away from the disc, which tells me that it’s sensitive rather than resistant. The final test that I did was a CAMP test. That CAMP test was incubated at the same time as the bacitracin test, after observing the plate I found the …show more content…
(Todar 1). About five to fifteen percent of people have Streptococcus bacterium within their respiratory tract, but do not have any signs or symptoms (Todar 1). Streptococcus pyogenes is transmitted trough respiratory droplets; it can also be spread to cattle and back to humans’ trough unpasteurized milk or raw meat (Pathogen Regulation Directorate).
There are many diseases in the ranges of mild to severe that Streptococcus pyogenes can cause. Some acute diseases include cellulitis, impetigo, sinusitis, and strep throat (Khan). Some more severe diseases that the bacteria can cause are necrotizing fasciitis, vaginitis, and scarlet fever (Khan). Some common signs and symptoms include fever, pain, dizziness, or a red rash around a wound (Streptococcus pyogenes).
Streptococcus pyogenes has many virulence factors to help it survive within a human host. There’s a M protein, which allows Streptococcus pyogenes to resist phagocytosis (Todar). The F protein allows to bacteria to attach to epithelial cells. Another virulence factor is the hyaluronic acid capsule that helps the organism be resistant to phagocytosis as well; the capsule is similar to human connective tissue so the immune system doesn’t recognize it (Reese). To escape antibiotics the tagged epithelial cells with the F protein form biofilms so they aren’t phagocytized (Streptococcus pyogenes). Streptococcus pyogenes