Which among the following is an anaerobic bacteria?
High-Yield Explanation
Corynebacterium diphtheriae is an aerobic and facultative anaerobic gram positive rod that appear club shaped. They are arranged in V or L shaped formations. The rods have a beaded appearance and the beads consist of granules of highly polymerized polyphosphate. These granules stain metachromatically. It is transmitted through airborne droplets. It can also infect the skin at the site of a preexisting skin lesion. It produces a toxin which inhibits protein synthesis by ADP-ribosylation of elongation factor 2 (EF-2). It can be cultured on Loeffler's medium, a tellurite plate, and a blood agar plate. The typical gray-black color of tellurium in the colony is a telltale diagnostic criterion. Methylene blue staining shows tapered, pleomorphic gram-positive rods and it can also reveal the typical metachromatic granules. Ref: Levinson W. (2012). Chapter 17. Gram-Positive Rods. In W. Levinson (Ed),Review of Medical Microbiology & Immunology, 12e.