ABSTRACT This lab will be a review of the work of Yamaguchi et al. in their work with observing the overall characteristics, necessities for growth, and more specifically the invasion patterns of Streptococcus pneumoniae in the presence of erythrocytes; one of the most common type of blood cell in human blood (1).

INTRODUCTION Streptococcus pneumoniae is a gram-positive bacterium, meaning it lacks an outer membrane making it more susceptible to antibiotics, which is related to many infectious diseases. S. pneumoniae has a very high rate of recombination meaning it is able to adapt to medicine in a short span of time. Previous research about the erythrocytes, hey in the transfer of oxygen and carbon dioxide during cellular respiration, shows that they are involved in the successful growth of bacteria due to its high concentration of iron. (2). Yamaguchi et al. found that iron within erythrocytes partially inhibit the growth of S. pneumoniae due to the free-radicals made between the interaction of iron and hydrogen peroxide. It was also found that in the presence of erythrocytes, the growth of S. pneumoniae increases substantially, as well as a new invasion strategy employed by S. …show more content…
were that S. pneumoniae growth increases by a factor of 3 in the presence of erythrocytes, and specifically is best in an environment which lacks iron ions and lysed erythrocytes (Figure 1). This can be due to the fact that iron ions create hydroxyl radicals in high concentrations and in contact with hydrogen peroxide. The free-radicals can disrupt the growth pathway within the bacterium thus causing a smaller viable colony count. When incubated with hemoglobin and lysed or membrane-having erythrocytes, this previous result was confirmed also showing that S. pneumoniae is inhibited by the presence of lysed erythrocytes and iron ions, specifically free radicals which are present in