ASCP Technologist in Microbiology (M) Practice Exam 2025 – Comprehensive All-in-One Guide to Exam Success!

Corynebacterium diphtheriae is characterized as a Gram-positive bacilli, which is crucial for its identification in laboratory settings. The characteristics of the gram stain involve the retention of certain crystal violet stains in the bacterial cell wall, which is thick in Gram-positive bacteria due to peptidoglycan layers. When Gram-stained, Corynebacterium diphtheriae appears as rod-shaped (bacilli) organisms that retain the violet stain, appearing purple under the microscope.

This gram-positive classification is significant not only for diagnosis but also for determining the most effective treatment options, as the Gram-positive nature can influence susceptibility to various antibiotics. In clinical microbiology, accurate identification of Corynebacterium diphtheriae is essential, as this bacterium is responsible for diphtheria, a serious respiratory illness. Therefore, recognizing its Gram-positive bacilli characteristic aids healthcare professionals in making informed decisions regarding patient care and management.