- Clostridium perfringes. Clostridium perfringes, also known as C.
perfringes, causes myonecrosis—better known as gas gangrene—which
produces hydrogen gas in deep tissue wounds, resulting in cell death. - Clostridium botulinum.Clostridium botulinum, also known as C. botu-
linumis a cause of food poisoning usually as a result of improperly
canned food. It produces an exotoxin that causes flaccid paralysis
(weakness of muscle tone) due to the suppression of acetylcholine,
which is a neurotransmitter. The result is vomiting, difficulty speaking,
and difficulty swallowing, which can lead to respiratory paralysis and
death. Physicians useClostridium botulinumas a neural block that
inhibits muscle contraction. Clostridium botilinumis also used cosmet-
ically to relax muscles that cause facial wrinkles (Botox injections). The
C. botulinumtoxin blocks the exocytosis of synaptic vesicle of the neu-
romuscular junction, where motor neurons meet muscle.
Regular Nonsporing Gram-Positive Rods
Regular, non-sporing gram-positive rods are obligate or facultative anaerobes
that have a rod-shaped appearance as is implied by its name. They inhabit fer-
menting plants and animal products. There are four genera within this section.
These are:
- The genus, Lactobacillusare non-sporing gram-positive rods. These are
aerotolerant bacteria that produce lactic acid from simple carbohydrates.
The acidity inhibits competing bacteria. An example of a Lactobacillus
organism is the species Lactobacillus acidophilus. - Lactobacillus acidophilusis found in the human intestinal tract, oral cav-
ity and adult vagina. They produce an acidic environment that inhibits the
growth of harmful bacteria by fermenting glycogen into lactic acid.
Lactobacillus acidophilusis also used commercially to produce an assort-
ment of food products including sauerkraut, pickles, buttermilk and yogurt.
Other examples of regular non-sporing gram-positive rod bacteria are:- Listeria monocytogenes. Listeria monocytogenescontaminates food and
dairy products, if ingested can cause the disease listeriosis, which causes
an inflammation of the brain and meninges (meningitis).
CHAPTER 10 The Prokaryotes^163