Which type of bacteria is Xylella fastidiosa classified as?

Xylella fastidiosa is classified as Gram-negative bacilli, which means it has a specific bacterial cell wall structure that does not retain the crystal violet stain used in the Gram staining procedure. This characteristic is significant because it influences how the bacteria grow, their susceptibility to antibiotics, and their interactions with hosts and vectors.

Understanding that Xylella fastidiosa is a Gram-negative organism also helps in recognizing its pathogenic mechanisms and the diseases it causes in various plants, such as Pierce's disease in grapes. The classification as bacilli indicates that the bacteria have a rod-like shape, which is essential for identifying this pathogen in diagnostic procedures.

While Xylella fastidiosa is indeed phloem-limited, which refers to its residence and movement within the plant vascular system, the question specifically seeks its classification regarding cell structure rather than its ecological niche. Additionally, the options of rod-shaped fungi and Gram-positive cocci do not apply to Xylella fastidiosa at all, as fungi represent a separate kingdom and do not relate to this bacterium's classification. Moreover, Gram-positive cocci describe a different group of bacteria with a distinct cell wall that retains the crystal violet stain, further highlighting that Gram-negative bacilli is the appropriate classification for