What is the type of hemolysis described as a small zone of alpha-hemolysis surrounded by a zone of beta-hemolysis after refrigeration?

The described hemolysis pattern is known as alpha-prime hemolysis. This specific type of hemolysis occurs when certain bacteria, particularly Streptococcus pneumoniae, undergoes a transformation after refrigeration. Upon being stored at lower temperatures, these bacteria display a small zone of alpha-hemolysis—indicating partial breakdown of red blood cells—surrounded by a larger zone of beta-hemolysis, which reflects complete lysis.

Alpha-prime hemolysis thus signifies a dual pattern where the alpha-hemolytic activity is promoted under specific conditions, such as chilled environments, compelling the bacteria to alter their hemolytic capabilities. This transition showcases not only the complex behaviors of bacterial species but also how environmental factors can influence their characteristics.

In contrast, the other choices represent distinct hemolytic behaviors that do not align with the described phenomenon. Gamma-hemolysis indicates no hemolytic activity at all, beta-hemolysis reflects complete destruction of red blood cells without any partial breakdown, and alpha-hemolysis shows only partial lysis without the additional beta-hemolytic activity. Thus, the classification of alpha-prime hemolysis accurately captures the unique characteristics arising from the refrigeration context in this situation