Microbiology: Tetanus and Clostridium tetani

Flashcards covering the pathogenesis, clinical features, lab diagnosis, and prevention of Tetanus based on the provided lecture notes.

Clostridium tetani

A Gram +ve bacilli and obligate anaerobe that appears with a drum-stick appearance due to a terminal round spore.

Tetanospasmin

An exotoxin produced by C. tetani that is internalized at motor nerve endings, reaches GABA-producing inhibitory neuron terminals via retrograde transport, and inhibits the release of GABA, leading to excessive muscle contraction.

Tetanolysin

One of the two exotoxins produced by Clostridium tetani.

Trismus

A clinical feature of tetanus commonly referred to as lock jaw.

Risus sardonicus

A clinical feature of tetanus characterized by sustained facial muscle spasm.

Opisthotonos

A clinical position where the full body is in extension due to spasms of the trunk and limb muscles.

Blood agar with polymyxin B

A media used for culturing C. tetani, which produces hemolytic colonies with swarming.

Robertson cooked meat (RCM) broth

A culture media where meat particles turn black and produce a foul smell in the presence of C. tetani.

In vitro Toxigenicity test

A test performed on Blood agar media where anti-tetanolysin antitoxin is spread over half of the media; hemolysis does not occur on the antitoxin half if C. tetani is present.

In vivo Toxigenicity test

A test where the tail of a mouse is inoculated with a culture of C. tetani, resulting in spasms (first in the tail) within $24\,\text{hrs}$.

Pentavalent vaccine

A vaccine included in the National Immunization Schedule (NIS) 2020, administered at $6$, $10$, and $14$ weeks.

Td vaccine schedule (NIS 2020)

Administered at $10\,\text{Y}$ and $16\,\text{Y}$.

HTIG

Human Tetanus Immune Globulin, which is administered alongside a Td dose if a wound is $> 1\,\text{cm}$ deep/contaminated and the vaccination status is unknown or the last vaccine was taken more than $10\,\text{Y}$ ago.