September 2023

Bacteria
Actinotignum schaalii: a new pathogen

An emerging pathogen Actinotignum schaalii gram stain (pic Manurx27, Wikipedia) What infection does it cause, and who is mostly affected? How to identify Actinotignum schaalii in the lab? How do we treat infection caused by Actinotignum schaalii infection? Actinotignum schaalii presentation.(Youtube)

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Bacteria
Pneumococcus - gallery

Streptococcus pneumoniae or pneumococci are gram-positive cocci in pairs, which may be capsulated. Colonies are 1-2mm, α-haemolytic and may appear as ‘draughtsman’ colonies (due to autolysis of the organisms). If incubated in anaerobic conditions, the colonies may appear larger and more mucoid. It is, like other Streptococcus spp., catalase-negative. Traditionally, a few of the properties of the pneumococcus were exploited to […]

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Bacteria
Paracoccus Yeei

Paracoccus yeei is an aerobic Gram-negative coccobacilli typically found in soil and brine. It appears as diplococci and may have a visible vacuole – giving an “O” shaped appearance. It may under-decolourise and appear as Gram-positive cocci. It is oxidase-positive and confused with Moraxella/Neisseria. Identification can be made using automated systems like VITEK-2 GN, MALDI-ToF and DNA […]

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