Wednesday, February 18, 2009

BACTERIA

When Alexander Fleming found penicillin accidentally in 1928, the world was pleased to know that they have found a remedy to all the hell broke loose by many bacterial infections and diseases back then.
The breakthrough gave Alexander Fleming together with his associates of Ernst Boris Chain and Howard Walter Florey were celebrated with a Nobel Prize in Physiology and Medicine in 1945. Since then penicillin was renowned as the primary remedy for any cases of bacterial infection and diseases related to it.

Bacteria is a large group of unicellular microorganisms that ranges from different size, shape, physiology and functions. All thanks to Antoine van Leeuwenhoek, the first person to observe bacteria using a microscope. Together with the rapid changes in the world of science, we have seem to know more about them.

There are approximately ten times as many as bacterial cells as human cells in the body. Majority are harmless, friendly and protected against human cells by our very own immune system. Some caused potential deadly infection to very mild degree of infections. Our skin, digestive system, respiratory system and mouth were a bulk-pool of bacteria infestation site and therefore infections are commonly seen here.

Bacteria is classified in generally to include those under gram positive (no outer membrane) and gram negative (with outer membrane), which were based on test using gram staining. Other unrecognized types of bacteria were also noted.

Let's look at some of the most commonly talked about bacteria in our life. It may be as famous as syphillis or it can be some historic lesson as in Bubonic plague.

#1 - Bacillus anthracis >> Anthrax

This bacteria of rod-shaped Gram-positive causes an acute disease called anthrax. It was the oldest recorded disease among the grazing animals such as sheep and cattle and have some to believe it was the reference to the Sixth Plague mentioned in the Book of Exodus. In 1877, Robert Koch discovered this bacteria can cause disease in human and was later awarded a Nobel Prize. Anthrax is spread via ingestion into intestines, inhalation into the lungs or via skin.

Prevention:
cannot spread from person to person but dead body is a potential infection source, vaccination available
Treatment: Fluoroquinolones, doxycycline, penicillin, erythromycin or vancomycin


#2 - Treponema pallidum >> Syphillis

Sexually transmitted disease, syphillis is caused by this gram-negative spiral-shaped. Predominantly, syphillis is acquired by sexual contact with the infectious person and in some case via congenitally from mother-to-children. Syphillis occured in three stages; primary, secondary and tertiary. Traditionally, the disease was dubbed as the 'Great Imitator' due to its confusing nature with other disease, especially in the tertiary stage. Syphillis remain to occur in the world today despite introduction of condom and promotion of safe sex practise.

Prevention:
safe sex, no vaccination available
Treatment: Penicillin G, ceftriaxone


#3 - Yersinia pestis >> Bubonic plague

The bubonic plague is an infection of the lymphatic system resulting from the bite of flea. Fleas are commonly found in rodents and poor hygiene is one of the factor why it was once so wide-spread occurred. Experts believe that the Black Death that swept through Europe in the 1340s were actually due to this. Black Death causes the deadliest human pandemic disease in history, killing about 75 million people, mostly in Europe. The bacteria is a Gram-negative rod-shaped.

Treatment: Streptomycin, gentamicin, ciprofloxacin, doxycycline


#4 - Mycobacterium tuberculosis >> Tuberculosis
Tuberculosis (TB) is a disease that attacks the lung and may later spread elsewhere in the body. The culprit is this typical mycobacterium strain which is requires high level of oxygen; neither Gram positive nor negative, rather a special acid-fast technique is used to recognize it. The disease is spread via sputum or inhalation, or even via close contact. Although the disease can be controlled, it still claims more than 1.5 million life annually.

Prevention: Vaccination with Bacillus Calmette-Guerin (BCG), avoid close contact
Treatment: Rifampicin, isoniazid, pyrazinamide, streptomycin


#5 - Escherichia coli >> Food poisoning, diarrhea

This Gram negative oblongated bacterium is commonly found in lower intestine, mostly harmless. However certain strains are known to cause the disease. Found in 1885 by Theodor Escherich, the bacterium is in fact the most studied micro-organisms due to its simplicity in genome and genetic modification. Food poisoning is usually due to its toxin, however may cause notorious complications like hemolytic-uremic syndrome.

Prevention: Personal hygiene, food hygiene
Treatment: Amoxicillin, cephalosporins, trimethoprim-sulfamethoxazole, ciprofloxacin

There are many more bacterial infection which are common in human body. This include Pseudomonas aeruginosa which causes generalized inflammation and sepsis; Helicobacter pylori which causes peptic ulcer or gastric; Streptococcus pyogenes which causes cellulitis, erysipelas and rheumatic fever;and the list just goes on and on.

It is hard to know all but at least if we know a handful of them, it may be vital for knowing how to manage cases of bacterial infection and what are the precautions. I am sure you heard about the Brazilian model whom died last month due to septic shock originated from a simple undiagnosed bacterial infection. Again, a boy was died due to another bacterial infection following fever while waiting for his plane home to Hong Kong in KLIA.

Well, not to frighten you with all of these threatful pictures of how nasty bacteria can be but precautions must be taken, don't you agree! [Credits to related articles from Wikipedia, my Microbiology notes and bible]

3 comments:

Shuuu said...

Somehow i find all these bacteria pictures interesting haha. curious me haha

acura said...

Anthrax is also the preferred bacteria for a biological attack

sirei said...

*flipping bio textbooks....

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