Clostridium botulinum

Description and Significance

Clostridum botulinum are Gram-positive rod-shaped bacteria. It falls in the family of gram-positive bacilli. This bacteria produce a neurotoxin which could lead to paralysis. Clostridum botulinum are based on seven different types falling from A through G and further categorized into four distinct groups. Out of the four groups, group one and two tend to have the highest occurence rate. Group one lives in an ideal temperature of 37 degress Celsius and once the temperature becomes hotter spores begin to form. Group two grow optimally in a lower temperature around 30 degrees Celsius and grows spores once the temperature drops. Group three is usually found amongst animals excluding humans. Group four of Clostridium botulinum are being re-evaluated to see if they truly cause any type of disease. Both group three and four have favorable conditions at 40 degrees celsius. This bacteria,Cl. botulinum is an obligate anaerobic bacteria, that produces endospores, and releases a superoxide dismutase which allows the bacteria to survive in unfavorable conditions. Cl. botulinum is normally grown in soil and water enviornments.

Genome Structure

The genome of Clostridum botulinum was sequenced due to the many unique abilities that this bacteria retains. This bacteria forms the foodborne illness called Botulism.^[2] Scientists have illustrated many studies regarding the four different groups of Cl. botulinum. The size of this bacteria is relatively large. This feature is thought to be large do to the ability to form spores and the skill to produce toxins. Genomic analysis by pulse-field gel electrophoresis revealed genes encoding neurotoxin, hemagglutinin A, and genese for a temperate phage, and various transposon Tn916 sites. ^[3]

Cell Structure and Metabolism

Clostridum botulinum are single rod stranded gram positive anaerobic bacteria. When the proper environment is not met this bacteria lies in its latent stage. The ideal environment is moist, with very little oxygen in a mesophilic climate. An example of this type of environment is in soil and marine environments. Considering a favorable place of habitat for Clostridum botulinum is soil, it allows the idea that this bacteria can pollute the surrounding soil and effect many crops that are grown. Each categorized group is best grown in different set temperatures. Clostridum botulinum is spore forming, and can resist harsh environments do to the superoxide dismutase. Additionally, do to the formation of spores the bacteria is protected against harsh conditions. After the formation of spores, the spores will release toxins leading to food borne illnesses.^[3]

Ecology

Clostridium botulinum is a bacteria that has an incomparable effect on the environment. They are able to interrupt the ecosystem by invading and contaminating many foods eaten, however it can greatly improved someone’s life.

Generally, Clostridium botulinum has a negative consequence on the environment. There are seven types of Clostridium botulinum, however type 5, E, is the type that causes spores and eventually causes a release of toxins. “In order for proliferation to occur, the spores need to be present in non-halophilic salinity and anaerobic conditions.” ^[3] The endospore forming group is type E, which is found in soil and can affect plants and other habitats such as beaches. ^[1] It was found on 5 out of every 12 beaches in Alaska and was found in the gills of many fish, such as salmon. Furthermore, in another study found in the Applied and Environmental Microbiology, 14 out of 47 farmlands contained the bacteria Clostridium botulinum. ^[4] This bacteria effects the nervous system, by effecting the release of the neurotransmitter acetylcholine. Without acetylcholine muscles will not contract and paralysis can occur. ^[6] The spores can effect almost every food. When infected with Clostridium botulinum common symptoms include, nausea, vomiting, weakness, double vision, and difficulty speaking and swallowing. ^[5]

On the other hand, Clostridium botulinum has some positive attributes. This is commonly known as botox. Botox can treat nervous muscle related twitches, as well as sporadic muscle tensions. The blepharospasm is an involuntary muscle in the eye that forces the eyelid closed. On a personal level, Botox can also treat facial wrinkles. ^[6]

The way botox works is by injecting it intramuscularly, hence never entering the blood stream. Before doing this a full physical exam and many comprehensive questions must be asked. The only known side effect is muscle weakness.

Pathology

Clostridium botulinum is a bacteria leading to Botulism. Out of the seven different types of this one bacteria, types A, B and E are pathogenic in human. This related to groups one and two are dangerous towards humans. When infected with Clostridium botulinum, the bacteria automatically will bind to the presynaptic nerve terminal which is the neuromuscular junction. The bacteria prevents acetylcholine from binding to this presynaptic nerve terminal which relaxes the muscles and prevents it from contracting. ^[7] The toxins are further digested trough the gastrointestinal tract and are denatured causing stomach problems, such as constipation. ^[8]

Any individual can come in contact with Clostridium botulinum, either willingly or unfortunately. There are three ways to come in contact with the disease besides willingly getting injected with it: aerosol spread during warfare, wound infection and food borne illness. ^[7] Transmission can occur with the spread of aerosol during a time of warfare as a biological toxin. Additionally, during trauma Clostridium botulinum can be spread through wound infections. Lastly, ingesting the toxin would be considered a food borne illness. There are a few ways of getting Cl. Botulinum as a food borne illness. These ways include infant botulism (by ingesting honey), improperly preserved food cans, crops from polluted soil, meats, vegetables and fruits grown in contaminated places. ^[7]

Application to Biotechnology

Clostridium botulinum strand A is being used now to treat both muscle problems, as well as lessening wrinkles. In 1949, Dr.Burgen’s discovered that botulinum blocks neuromuscular transmissions. The following year it was found that when injected into a nerve ending it will block the acetylcholine from the neuromuscular junction. In the next 30 years Dr. Alan B. Scott, of Smith-Kettlewell Eye Research Institute, used botulinum for the first time in humans to treat strabismus, which is a deviation from normal vision. Within the next ten years, botulinum was used for many other eye and facial conditions. These conditions were strabismus blepharospasm, cervical dystonia and hemifacial spasm. In the year 2001 botulinum was used for excessive sweating called axillary hyperhidrosis.^[9] In addition, to medical treatments it also was linked to reducing wrinkles and eyebrow lines in 2001. Although, in the United States it has not been approved, botulinum is used to treat chronic muscle pain disorders in Europe. Lastly, current research is being performed to see if any other strand of botulinum can be used to help or treat various conditions besides category A. ^[9]