Ben B. Artuz Therese Anne B. Checa Nerfe Gem E. Osano (April 2015)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Staphylococcus aureus is a biofilm-forming bacterium. Biofilms are community of microorganisms encased in an extracellular matrix that is attached to a surface. There is a point in biofilm formation where cells detach from the biofilm and colonize other sites, spreading the infection. The dispersion is the least studied among the phases of biofilm formation. Furthermore, little had been done to characterize the cells detached from the biofilm. The objective of this study is to compare the aggregation of the biofilm-detached cells from that of planktonic cells. Cells were harvested from a 2-day old biofilm and its aggregation was compared to that of the suspension-grown cells. An autoaggregation assay was used to measure the aggregation percentages. Then the aggregation percentages where plotted in a time-percent aggregation graph and fitted to an exponential association model. The aggregation rate was then determined from the model. After the 5 hour interval, the percent aggregation of the biofilm- derived cells (100) is higher compared to that of suspension-grown cells (73.83). The aggregation rate of the suspension-grown cells is 51.68 and 53.65 for the biofilm-derived cells. The aggregation rate of the two groups is not significantly different. Even though biofilm- derived cells had higher aggregation percentages than suspension-grown cells, the rate in which they aggregate is comparable. This result would indicate that biofilm-derived cells and suspension-grown cells aggregation is not different from one another. Biofilm-derived cells do not exhibit a different aggregation ability compared to their planktonic counterpart. Cells detaching from the biofilm retains the characteristics of their planktonic form.