How quickly can bacterial contamination occur?

How quickly can bacterial contamination occur?

A. 5-10 seconds

B. 5-10 minutes

C. 10-20 seconds

D. 10-20 minutes

Answer: D. 10-20 minutes

Bacterial contamination happens quite quickly, usually after 10-20 minutes of exposure. However, in the presence of new environment such as leftover food at room temperature bacterial cells undergo rapid reproduction through binary fission. In this process, bacterium splits into two daughter cells that continue undergoing cell division exponential. Starting from a few cells, millions can appear within minutes.

These include factors such as temperature, pH value, oxygen content and nutrient availability that affect the growth rate of bacteria. Most foodborne pathogens flourish in temperatures between 40°-140°. The best pH values are those around 7, and the necessary presence of water with nutrients such as carbohydrates, proteins, fats is also favorable. In favorable circumstances, bacteria such as E. coli and Salmonella multiply their number every 20 minutes.

Apart from fast multiplication, bacteria can transfer directly and indirectly by contact. For instance, raw chicken on a cutting board can contaminate within minutes through transfer of bacteria to utensils, hands and other foods. Proper food safety involves the control of time and temperature so as to avoid this rapid bacterial contamination. In the kitchen, it is critical to refrigerate perishable foods; clean surfaces and prevent cross-contamination. Watchfulness means that, while the threat persists only over a short period of time, bacterial contamination can be greatly reduced.